回复：第2题...请逻辑好的高手给解释一下.

Argument #: there are living communities of microorganisms there that have been cut off from surface life for millions of years.

Supporting Fact#: the discovery of living microorganisms in samples of material that were taken from holes drilled as deep as 1.74 miles.

One may argue that the samples used for supporting the claims by scientists may be from different depths or surface soil during the drilling process, which weakens the claim.

Thus, you need C as an assumption.

option E is irrelavent to the claim.