人类的“立足点”是生物圈的[ ]

A．水圈

B．大气圈

C．岩石圈的表面

D．在生物圈的任何地方

After that, he knew he could ____ any emergency by doing what he could to the best of his ability. [ ]

A. get away with

B. get on with

C. get through

D. get across