Since it is one of the world’s swiftest growers, gains up to 1 meter a day, and can be harvested in under ten years, half the time taken for the softest woods to mature, experts indicate that bamboo, China’s forgotten plant, should be considered “green gold”.
This is a tough question, but let's break it down to get to the right answer:
MEANINGBamboo...
1) is one of the fastest growers
2) gains up to 1 meter a day
3) can be harvested in under 10 years
i) which is half the time taken for the softest woods to mature
Once we understand the overall meaning of the sentence, let's dig each answer choice deeper and analyze issues:
A.
gains up to 1 meter a day, and can be harvested in under ten years, half the time taken
If you think about it, "gains up to 1 meter a day" is not a distinct feature that separates from 1) discussed above. This is an additional information related to 1), and hence it's not preferred to use "gains up to 1 meter a day". Here, you want to modify 1) by using "comma verb-ing" to correctly modify 1).
B. gaining up to 1 meter a day, and can be harvested in under ten years, half the time it takes
Correct answer
For those of who eliminated B because of this annoying "it" at the end, "it" is the same as "half the time that it takes". What difference does it make? it is a placeholder pronoun, so it's okay to keep "it" there.
C.
gains up to 1 meter a day, and
harvests in under ten years, which is half the time taken
Same error as A and the usage of "harvests" is wrong because a bamboo does not harvests itself.
D.
gaining daily up to 1 meter and
harvesting in under ten years, half of the time taken
The usage of "harvesting" here is not correct because harvesting in under ten years does not logically modify the previous clause, "one of the swiftest growers". Also, this is very subtle, but "gaining daily up to 1 meter" slightly changes the meaning.
E. gaining up to 1 meter a day
so that it can be harvested in under ten years, half the time taken
"so that it can be harvested" distorts the intended meaning.
Again, this is a very tough question, and I hope my explanation helps shed some light.