Lyme disease is caused by a bacterium transmitted to humans : GMAT Critical Reasoning (CR)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 19 Jan 2017, 20:03

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Lyme disease is caused by a bacterium transmitted to humans

Author Message
TAGS:

### Hide Tags

Manager
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 1

Kudos [?]: 101 [3] , given: 1

Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

21 Jul 2009, 21:18
3
KUDOS
40
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

40% (02:09) correct 60% (01:35) wrong based on 999 sessions

### HideShow timer Statistics

Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.
[Reveal] Spoiler: OA

Last edited by carcass on 30 Dec 2014, 03:44, edited 2 times in total.
If you have any questions
New!
Senior Manager
Joined: 04 Jun 2008
Posts: 303
Followers: 6

Kudos [?]: 134 [7] , given: 15

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

23 Jul 2009, 16:58
7
KUDOS
1
This post was
BOOKMARKED
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]

Good question.

B IMO

Say the size of deer tick is limited by availability of animals, ie, if there were more animals to feed upon, their would be more deer ticks, but because there is less food, population of deer ticks is limited. Then when uninfected food (animals) increases, uninfected deer tick population will increase.

However, if the deer tick already has sufficient food (infected or uninfected) there is no guarantee that the tick will feed on the extra uninfected animals. So no guarantee that extra uninfected animals will increase uninfected tick population.
Intern
Joined: 04 Aug 2010
Posts: 23
Schools: Dartmouth College
Followers: 13

Kudos [?]: 67 [7] , given: 0

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

20 Aug 2010, 14:51
7
KUDOS
3
This post was
BOOKMARKED
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

Conclusion: If the population of the other species increased, the number of ticks acquiring the bacterium would decline.

Premises: The other species do not harbor the bacterium. The ticks generally acquire the bacterium while feeding in the larval stages.

Assumption: That the ticks will feed on the the other species if given the opportunity to do so.

Prediction: The correct answer will address the assumption and strengthen or weaken the conclusion. It will show whether the ticks actually will feed on the other species.

To understand the answer choices more easily, rephrase them without the word whether.

(A) The populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice. Doesn't help us determine whether the ticks will feed on the other species.
(B) The size of the deer tick population is not currently limited by the availability of animals for the tick's larval stage to feed on. In other words, the ticks have plenty of food; the number of ticks is not being held back by the amount of food available. Thus, more food will NOT lead to more ticks. Implication: Any larvae that eat the uninfected food will not increase the total population of ticks but will instead DECREASE the number of ticks getting infected, STRENGTHENING the conclusion that the number of infected ticks will decrease. CORRECT.
(C) The infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice. Outside the scope. The argument is not about how the population can be controlled but about whether the population would increase.
(D) The deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed. Tempting, but incorrect. The argument states that the way the ticks generally get infected is by feeding in the larval stages. This is a premise of the argument and cannot be disputed. Any answer choice that discusses other ways the ticks can get infected is irrelevant. Even if ticks can get infected as adults, this is not the way ticks generally get infected, so who cares? A word of advice: an answer choice that attacks a premise will not be correct. The correct answer will address the assumption, which in this case is that the ticks will feed on the other species.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans. Out of scope. The argument isn't about other bacteria.

Hope this helps!

Mitch Hunt
GMAT tutor and instructor
New York, NY
_________________

GMAT Tutor and Instructor
GMATGuruNY@gmail.com
New York, NY

Last edited by GMATGuruNY on 27 Dec 2014, 08:12, edited 1 time in total.
Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 644
Location: Cambridge, MA
Followers: 83

Kudos [?]: 276 [2] , given: 2

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

28 Nov 2009, 10:44
2
KUDOS
Expert's post
Good questions!

The larva of the tick "generally pick up the bacteria" from feeding on white footed mice--here, 'infected' and 'acquiring the bacteria' are synonyms.

So, if we have 1000 ticks feeding on the white-footed mice, we'll see infection. Some percentage of the mice will have the bacteria, and some percentage of the ticks feeding on those mice will acquire the bug. These percentages are a constant. So if 1000 ticks feeding on white-footed mice produce n infected ticks, then 500 will produce 1/2 n and 2000 will produce 2n. In other words, the plan is trying to reduce the number of infected ticks be reducing the number of ticks feeding on white-footed mice.

Since in the first case I described, introducing a non-carrier species for ticks to feed on would reduce the number of ticks drinking infected blood, but in the second case it would not, (B) is a central determinant to the success or failure of the plan. I hope that helps!
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save $150 on a course! Kaplan Reviews Director Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing. Affiliations: University of Chicago Booth School of Business Joined: 26 Nov 2009 Posts: 997 Location: Singapore Followers: 22 Kudos [?]: 747 [2] , given: 36 Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] ### Show Tags 09 Aug 2010, 22:48 2 This post received KUDOS In GMAT if any answer choice is asking you to bend backwards then probably its wrong - there will be herculean amount of thinking in 2 mins. That's not the technique used to crack. D means many things hypothetically - 1) The infected number is going to first decrease and then at later point increase linearly causing the final number of infected ticks to remain the same 2) The infected number is going to decrease. Later time when the adults get infected the number is going to rise exponentially. Basically D depends on lady luck and can take either sides. So D is not the answer. The most important thing is D is a shift in the focus of the argument. nikhilkatira wrote: nusmavrik wrote: Food is the bone of contention between the ticks and the third species. We need to evaluate whether the method can limit the population of deer ticks. I hope you got B easily. D is a scope shift. We are not here to ascertain the ultimate fate of the adolescent deer ticks. The argument here is to evaluate whether the method can limit the population of deer ticks based on the food they eat. nikhilkatira wrote: Agree that Option B is correct, but why is Option D incorrect ? thanks for the explanation, but I am still getting little confused...please help me where am i getting wrong ? The last sentence of the argument says"If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline. " So as per option D, what if ticks acquire bacterium after they become adults ? The overall number will increase... nusmavrik what am I missing ? _________________ Please press kudos if you like my post. Manager Joined: 15 Jun 2009 Posts: 163 Followers: 2 Kudos [?]: 50 [1] , given: 8 Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] ### Show Tags 23 Jul 2009, 01:28 1 This post received KUDOS AndersonBound wrote: Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline. Which of the following would it be most important to ascertain in evaluating the argument? (A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice. ....in the argument it is stated that "If the population of these species increased, more of the larvae would be feeding on uninfected hosts" ...it means that tehy are feeding on infected mice bcoz there is not enough unifected host... (B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on....we r not concerned abt population (C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.......it cannot be inferrrd fom argument (D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed. ...correct ...bocz if adult ticks can pick the bacteria from dear..then number of infected ticks will not decline. (E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans....out of scope [Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????] IMO D....OA plz Kaplan GMAT Instructor Joined: 25 Aug 2009 Posts: 644 Location: Cambridge, MA Followers: 83 Kudos [?]: 276 [1] , given: 2 Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] ### Show Tags 10 Nov 2009, 21:29 1 This post received KUDOS Expert's post 1 This post was BOOKMARKED AndersonBound wrote: Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline. Which of the following would it be most important to ascertain in evaluating the argument? (B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on. The difficulty here is that the conclusion is about the NUMBER of ticks acquiring the bacterium, not their proportion. Imagine if some factor limits us to, say, 1000 ticks per acre. Maybe they are limited by water or by predators. In any event, if those 1000 ticks feed on 1000 white-footed mice, we have a 1000 infected ticks. On the other hand, if those ticks have a fifty/fifty shot of picking one of 1000 white-footed mice, or one of 1000 black-footed mice, then we'll have 500 infected ticks--substantially fewer, confirming the hypothesis. Now imagine that food is the limiting factor of ticks. We imagine each mouse can have one tick; in other words, we have a 1000 ticks because we have a 1000 white-footed mice. Now, we add 1000 black-footed mice, and suddenly there is food available 2000 ticks. We'll have a larger proportion that are uninfected, but the number that feed on white-footed mice remains unchanged at 1000. _________________ Eli Meyer Kaplan Teacher http://www.kaptest.com/GMAT Prepare with Kaplan and save$150 on a course!

Kaplan Reviews

Kaplan GMAT Instructor
Joined: 25 Aug 2009
Posts: 644
Location: Cambridge, MA
Followers: 83

Kudos [?]: 276 [1] , given: 2

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

27 Nov 2009, 21:25
1
KUDOS
Expert's post
jjoon1979 wrote:
OA is B!

This question is from the prep, but I still don't understand why OA is B..
Take a look at my explanation a few posts back, and let me know if I can clear up any specific issues about it.
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save \$150 on a course!

Kaplan Reviews

Intern
Joined: 10 Feb 2010
Posts: 34
Followers: 0

Kudos [?]: 2 [1] , given: 12

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

24 Jul 2010, 11:51
1
KUDOS
OA is B.
Attachments

v3.JPG [ 108.56 KiB | Viewed 7878 times ]

Manager
Joined: 16 Jun 2010
Posts: 171
Followers: 3

Kudos [?]: 39 [1] , given: 1

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

28 Jul 2010, 00:16
1
KUDOS
rashminet84 wrote:
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]

Good question.

B IMO

Say the size of deer tick is limited by availability of animals, ie, if there were more animals to feed upon, their would be more deer ticks, but because there is less food, population of deer ticks is limited. Then when uninfected food (animals) increases, uninfected deer tick population will increase.

However, if the deer tick already has sufficient food (infected or uninfected) there is no guarantee that the tick will feed on the extra uninfected animals. So no guarantee that extra uninfected animals will increase uninfected tick population.

Agree with B
_________________

R E S P E C T

Finally KISSedGMAT 700 times 450 to 700 An exprience

Current Student
Joined: 11 Oct 2013
Posts: 124
Concentration: Marketing, General Management
GMAT 1: 600 Q41 V31
Followers: 1

Kudos [?]: 51 [1] , given: 137

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

16 Dec 2015, 22:25
1
KUDOS
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

What do we want to check? - If increase in population of other species that the larva could feed on would decrease the infection!
Lets Evaluate B -
If the population of deer ticks is currently limited by availability of animals to feed on, then YES adding more animals would make sense.
If the population of deer ticks is currently not limited by availability of animals to feed on, i.e. there may be many animals already out there but the larva are still infected. In this case there is no point adding more animals in the area for the larva to feed on.

Hope this helps! +Kudos if it did
_________________

Its not over..

Manager
Joined: 27 Jun 2008
Posts: 158
Followers: 2

Kudos [?]: 30 [0], given: 11

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

21 Jul 2009, 22:46
Whats the statement of the problem?
Manager
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 1

Kudos [?]: 101 [0], given: 1

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

21 Jul 2009, 23:22
Oops. Updated. Thanks for the catch.
Current Student
Joined: 25 Nov 2007
Posts: 31
Location: India
Schools: ISB '17 (A), IIMA (A)
Followers: 0

Kudos [?]: 12 [0], given: 65

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

22 Jul 2009, 01:07
Is OA A?

Firstly, by POE.
Secondly, "(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice." because location of other species is important otherwise how would it be beneficial to increase the population of "other species" in some location while the deer ticks continue to feed on mice in another lcoation.

HTH.
Manager
Joined: 12 Jul 2009
Posts: 59
Followers: 1

Kudos [?]: 7 [0], given: 9

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

22 Jul 2009, 01:52
1
This post was
BOOKMARKED
B..i think

if the population of deer tick increases with addition of new species to feed, possibility of the disease increase further. The white mice population is not reduced anyway.
Intern
Joined: 06 Jul 2009
Posts: 33
Followers: 0

Kudos [?]: 9 [0], given: 0

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

22 Jul 2009, 11:58
IMO - A

The argument states that if population of other species increased, the number of ticks w/ bacterium would decrease. By POE, answer should be A because knowing whether other species are in areas where white footed mice inhabit could support or weaken the argument.
Manager
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 1

Kudos [?]: 101 [0], given: 1

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

23 Jul 2009, 14:34
Someone has provided the right answer.

HOWEVER, there is enough disagreement between answers that I would like to see more discussion around the answer choices.

Intern
Joined: 21 Jul 2009
Posts: 33
Followers: 9

Kudos [?]: 97 [0], given: 0

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

23 Jul 2009, 15:36
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]

Agree with A but largely through POE. Author's main argument: "If the population of these species [i.e., other species on which the larvae feed that do not harbor the bacterium] increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline."

My personal logic for A may seem a bit of a stretch, but the first two sentences of the paragraph imply that the tick is the agent for transmitting the bacteria. If the non-infected species are living amongst the white-footed mice (and, as a result, the ticks that are feeding off of these infected mice), these other species are at risk of acquiring the bacterium and, as a result, at risk of becoming just like the bacterium-infected white-footed mice themselves.

Reasons why others seem to be good candidates for elimination:

B.) This one looks like a trap because of the way that "population" is used. The author is not concerned with the deer tick population size but rather the population size of non-infected other species.

C.) Same as B - argument says if population of non-infected species increased -> number of ticks acquiring the bacterium decline. Nothing to do with population size of deer ticks.

D.) There's no mention of deer in the paragraph, just deer ticks. Looks like another trap. Would be more enticing if it mentioned general other species instead of deer specifically.

E.) The author's not concerned with other bacteria, only Lime Disease bacterium. After the first sentence ("Lyme disease is caused by a bacterium transmitted to humans by deer ticks"), each subsequent mention of bacterium is preceded by "the", meaning he is referring to the specific bacterium mentioned in the first sentence. His argument/conclusion is regarding Lyme disease bacterium.

Now.. what's the OA?
Senior Manager
Joined: 10 Dec 2008
Posts: 482
Location: United States
GMAT 1: 760 Q49 V44
GPA: 3.9
Followers: 40

Kudos [?]: 197 [0], given: 12

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

23 Jul 2009, 18:54
I don't know. B?
Manager
Joined: 10 Jul 2009
Posts: 169
Followers: 1

Kudos [?]: 82 [0], given: 8

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink]

### Show Tags

23 Jul 2009, 19:46
I would go for 'A'.
Re: Lyme disease is caused by a bacterium transmitted to humans   [#permalink] 23 Jul 2009, 19:46

Go to page    1   2   3   4    Next  [ 75 posts ]

Similar topics Replies Last post
Similar
Topics:
11 Lyme disease is caused by a bacterium transmitted to humans 21 31 Mar 2012, 09:32
15 Lyme disease is caused by a bacterium transmitted to humans 11 27 Feb 2012, 10:48
2 Lyme disease is caused by a bacterium transmitted to humans 1 06 Dec 2011, 22:25
15 Lyme disease is caused by a bacterium transmitted to humans 13 16 Oct 2009, 08:44
47 Lyme disease is caused by a bacterium transmitted to humans 17 20 Apr 2009, 18:17
Display posts from previous: Sort by