First opened in 1959, the St. Lawrence Seaway quickly became a vital s

Question

First opened in 1959, the St. Lawrence Seaway quickly became a vital shipping link between the Atlantic Ocean and the Great Lakes, enabling Canadian and American ports to transport grain, iron ore, coal, and steel. The convenience of shipping via the Seaway spurred industrial activity along the Great Lakes and the St. Lawrence River, creating an economic boom in the region. However, the decades since the Seaway's opening have been a time of ecological disaster for the fragile fresh water ecosystems of the Great Lakes. The St. Lawrence Seaway is a stunning example of the unforeseen effects that human activity can have on an environment.

Pollution in the Great Lakes has increased proportionally with heavier industrial activity, and waste from factories has raised the content of metals in the waters to unsafe levels. Diffuse source pollution, such as acid rain from car and smokestack emissions and runoff from polluted soil, has made the water more acidic. This has threatened the existence of several species that inhabit the region. But no one consequence of human activity has been as detrimental to the region as the introduction of exotic species, particularly the zebra mussel.

Zebra mussels are native to the Black and Caspian Seas of Eastern Europe. Their most notable characteristic is their ability to use iron found in seawater to form a natural adhesive that allows their bivalves to stick to almost anything, including the bottoms of oceangoing vessels, which were the unwitting carriers of this species into the Great Lakes via the St. Lawrence Seaway.

Since the first finding of zebra mussels in the Great Lakes in 1988, they have mushroomed into an environmental menace. Clinging to any surface with incredible tenacity, these mussels devour huge quantities of the phytoplankton required for survival by many native species. Zebra mussels also absorb pollutants through filter feeding, which they then pass on in toxic levels to predatory diving animals, such as ducks and fish.   1 
 1) The primary purpose of the passage is to

A) assert that the economic benefits of the St. Lawrence Seaway outweigh any potential ecological consequences
B) analyze the environmental consequences of the St. Lawrence Seaway and propose a possible solution
C) describe types of pollution in the Great Lakes region caused by the introduction of zebra mussels
D) emphasize the role of the St. Lawrence Seaway in the degradation of Great Lakes ecosystems
E) describe possible sources of pollution that are currently harming wildlife in the Great Lakes

2 
 2) According to the passage, all of the following have resulted from the opening of the St. Lawrence Seaway EXCEPT

A) The Great Lakes region has become a major source of grain, iron ore, coal, and steel.
B) It is now possible to ship goods to and from the Great Lakes region by water.
C) Exotic species have been introduced into the Great Lakes' ecosystems.
D) Levels of metals in the Great Lakes have become toxic.
E) The existence of several species has been threatened by increased pollution levels.

3 
 3) It can be inferred from the passage that the author would be most likely to agree with which of the following statements?

A) The St. Lawrence Seaway is directly responsible for increasing the acidity of the Great Lakes.
B) Shipping of industrial products by land from the Great Lakes region is less convenient than shipping by water.
C) The St. Lawrence Seaway has effectively revitalized an economically blighted region of the United States and Canada.
D) The St. Lawrence Seaway has allowed species native to the Great Lakes to become a nuisance to other waterways throughout the world.
E) Zebra mussels would never have become a problem in the Great Lakes region without the St. Lawrence Seaway.

Deeksharathore · Answer

In question 3, why do we choose B over E?

PassageRookie · Answer

Explanation 3. Question

(A) is out, because the second paragraph shows it was an indirect effect by the line: ''Diffuse source pollution, such as acid rain from car and smokestack emissions and runoff from polluted soil, has made the water more acidic.''

(B) is the correct answer. It can be found in the first paragraph ''The convenience of shipping via the Seaway spurred industrial activity along the Great Lakes and the St. Lawrence River, creating an economic boom in the region.''

(C) is out, because there is no mention in the passage about whether the economy of the region is blighted or not. Also it doesn't mention anything about revitalization of the economy in that region

(D) is out, because it is the exotic species '' zebra mussel'' being a nuisance not the native ones.

(E) is out, paragraph simply gives a brief information about the zebra mussel, how was it introduced to the Great Lake and how it became a nuisance to the other species but it doesn't imply it would  never  have become a problem in the Great Lakes region without the St. Lawrence Seaway.

CrackverbalGMAT · Answer

1) The primary purpose of the passage is to

The passage primarily talks about the establishment of the St Lawrence Seaway, highlights the ecological damage it has caused along with economic growth of the region and discusses one specific in which it has caused harm to the ecosystem of the Great Lakes.

A) assert that the economic benefits of the St. Lawrence Seaway outweigh any potential ecological consequences  The passage does not state which out of economic benefits and ecological damages outweighs the other. Eliminate.

B) analyze the environmental consequences of the St. Lawrence Seaway and propose a possible solution  The passage does not propose any solution to the environmental damage caused by the St Lawrence Seaway. Eliminate.

C) describe types of pollution in the Great Lakes region caused by the introduction of zebra mussels  The passage does not talk about various types of pollution caused by zebra mussels. Eliminate.

D) emphasize the role of the St. Lawrence Seaway in the degradation of Great Lakes ecosystems  Correct answer and consistent with out thinking above.

E) describe possible sources of pollution that are currently harming wildlife in the Great Lakes  The passage only talks about pollution from one source - the St Lawrence Seaway. Eliminate.

2) According to the passage, all of the following have resulted from the opening of the St. Lawrence Seaway EXCEPT

A) The Great Lakes region has become a major source of grain, iron ore, coal, and steel.  Correct answer. While the passage does state that these items are being transported, we do not know which is the source and which the destination.

B) It is now possible to ship goods to and from the Great Lakes region by water.  This is evident from the passage ("...St. Lawrence Seaway quickly became a vital shipping link between the Atlantic Ocean and the Great Lakes"). Eliminate.

C) Exotic species have been introduced into the Great Lakes' ecosystems.  This is evident from the passage ("...no one consequence of human activity has been as detrimental to the region as the introduction of exotic species, particularly the zebra mussel."). Eliminate.

D) Levels of metals in the Great Lakes have become toxic.  This is evident from the passage ("...waste from factories has raised the content of metals in the waters to unsafe levels."). Eliminate.

E) The existence of several species has been threatened by increased pollution levels.  This is evident from the passage ("Diffuse source pollution...has made the water more acidic. This has threatened the existence of several species that inhabit the region."). Eliminate.

3) It can be inferred from the passage that the author would be most likely to agree with which of the following statements?

A) The St. Lawrence Seaway is directly responsible for increasing the acidity of the Great Lakes.  Incorrect. Acidity is caused by sources such as cars, emissions and soil run offs as direct causes. Therefore, it is not the direct result of the St Lawrence Seaway, although it may be an indirect cause. Eliminate.

B) Shipping of industrial products by land from the Great Lakes region is less convenient than shipping by water.  Correct answer. This is evident from: "The convenience of shipping via the Seaway  spurred industrial activity  along the Great Lakes and the St. Lawrence River...". Prior to the Seaway, goods could have been shipped by land. But since the Seaway "spurred activity", we can infer that it was more convenient.

C) The St. Lawrence Seaway has effectively revitalized an economically blighted region of the United States and Canada.  We do not know if the region was "economically blighted" prior to the St Lawrence Seaway. Eliminate.

D) The St. Lawrence Seaway has allowed species native to the Great Lakes to become a nuisance to other waterways throughout the world.  No such information is provided by the passage. Eliminate.

E) Zebra mussels would never have become a problem in the Great Lakes region without the St. Lawrence Seaway.  No such information is provided by the passage. Eliminate.

Hope this helps.

gvij2017 · Answer

I am not sure how you come up with option B for Q-3. 
I understood that the convenience of shipping via the Seaway spurred industrial activity along the Great Lakes. 
But passage no where compared the convenience of seaway with that of road.

Can you explain how an insertion of external word (road) is valid for this comparison and make the inference correct with respect to this Q?
Your help can be great for me.

bM22 · Answer

Hi  gvij2017 ,

I agree that there is no comparison done on the convenience by road and water. The comparison is being inferred from the lines: "First opened in 1959, the St. Lawrence Seaway quickly  became a vital shipping link between the Atlantic Ocean and the Great Lakes, enabling Canadian and American ports to transport grain, iron ore, coal, and steel.   The convenience of shipping  via the Seaway spurred industrial activity along the Great Lakes and the St. Lawrence River,  creating an economic boom in the region. ", implying that if the seaway became so quickly vital for the transportation and created an economic boom in the region, there must have been some inconvenience with other shipping methods, thus making B, a better choice compared to other options.

Hope this Helps.
Thanks.

thegmatguy11 · Answer

What is the level of this passage? The passage was easy to understand and the questions weren't difficult to answer.

Sajjad1994 · Answer

In my opinion the difficulty level should be as such:

Question #1: 600
Question #2: 650
Question #3: 700

Overall: 650 (Medium)

AnirudhaS · Answer

Cause usage of the word “never” is too strong.

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First opened in 1959, the St. Lawrence Seaway quickly became a vital s

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First opened in 1959, the St. Lawrence Seaway quickly became a vital s

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