SC-species of cricket

[gmat009]

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.
A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly

[kris610]

I'd go with D. 'the number...rises and falls...., and ..it can" ..it again refers to the number of chirps.

[gmat009]

I'd go with D. 'the number...rises and falls...., and ..it can" ..it again refers to the number of chirps.

How you can say that "it" refers to "number of chirps" and not "temperature"

[stop@800]

to attract is correct
ABC out

in fact possibly as an approximate thermometer.
and
and it can in fact serve as an approximate thermometer.

I agree
There is some confusion with referrant of it
but all other choices have more errors.

I can't recall:
Do we have any such rule that it refers to closest noun?
Perhaps there is not

[wonder]

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.
A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly

'it' cannot refer to the no of chirps here because it wont be parallel then. if 'it' referred to no. of chirps, the it should have been followed by the verb "serves" and not "can in fact serve". the latter is not parallel with "rises and falls"

hence "it" clearly refers to temperature.

[stop@800]

In some species of cricket, the number of chirps per minute used by the male for attracting females
rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.
A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly

'it' cannot refer to the no of chirps here because it wont be parallel then. if 'it' referred to no. of chirps, the it should have been followed by the verb "serves" and not "can in fact serve". the latter is not parallel with "rises and falls"

hence "it" clearly refers to temperature.

I agree
my vote remains with D.

[gmat009]

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.
A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly

'it' cannot refer to the no of chirps here because it wont be parallel then. if 'it' referred to no. of chirps, the it should have been followed by the verb "serves" and not "can in fact serve". the latter is not parallel with "rises and falls"

hence "it" clearly refers to temperature.

I am not clear. "it" is Singular. "number of chirps" Singular and "temperature" Singular.
What's your point now..........

[eshahid]

to attract is correct constrcuction

eliminate A, B, C

first part of the sentence in D and E is correct, however E is missing a verb in the part of sentecne after comma.
D is the answer one must be looking for.

[dumb.doofus]

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.
A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly

'it' cannot refer to the no of chirps here because it wont be parallel then. if 'it' referred to no. of chirps, the it should have been followed by the verb "serves" and not "can in fact serve". the latter is not parallel with "rises and falls"

hence "it" clearly refers to temperature.

I am not clear. "it" is Singular. "number of chirps" Singular and "temperature" Singular.
What's your point now..........

I would disagree with wonder.. in fact I feel the explanation should be totally opposite to what wonder mentioned.

Thermometer is a device to measure temperature.. its the number of chirps and not the surrounding temperature that serve as a thermometer..because the number of chirps rises and falls based upon surrounding temperature.. the sentence clearly states that..

here "it" refers to the number of chirps.. with "can" we use the simplest form of the verb and so in this case.. we use "serve".. you never say, can serves.. that is incorrect..