Scientists have found that skin tissue is more resistant to toxic substances than lung tissue and uses sweat glands to protect the immune system from possible invaders.

A. skin tissue is more resistant to toxic substances than lung tissue and uses
--> meaning changed

B. skin tissue is more resistant to toxic substances than is lung tissue and uses
--> correct/concise/parallel

C. skin tissue is resistant to toxic substances, more so than lung tissue, using
--> awkward

D. the resistance of skin tissue to toxic substances is more than that of lung tissue, and it uses
--> use of "it" is wrong and ambiguous, rendering the sentence not parallel

E. the resistance of skin tissue to toxic substances is more than that of lung tissue, using
--> using wrongly modifies the resistance.

Source : Princeton Review[/quote]

killer1387 wrote:Scientists have found that skin tissue is more resistant to toxic substances than lung tissue and uses sweat glands to protect the immune system from possible invaders.

A. skin tissue is more resistant to toxic substances than lung tissue and uses
--> meaning changed

B. skin tissue is more resistant to toxic substances than is lung tissue and uses
--> correct/concise/parallel

C. skin tissue is resistant to toxic substances, more so than lung tissue, using
--> awkward

D. the resistance of skin tissue to toxic substances is more than that of lung tissue, and it uses
--> use of "it" is wrong and ambiguous, rendering the sentence not parallel

E. the resistance of skin tissue to toxic substances is more than that of lung tissue, using
--> using wrongly modifies the resistance.

Source : Princeton Review

But what does "uses" modify?

raptor1985 wrote: But what does "uses" modify?

SEE IT THIS WAY:

Main sentence intends to says about skin tissue
1.is more resistant to toxic substances than is lung tissue and
2.uses sweat glands to protect the immune system from possible invaders.

uses modifies skin tissue correctly as required by the meaning intended in the main sentence.

HTH

The answer has to be the only option that has parallelism in it.
skin resistance is more than lung tissue can't be right. Hence option B