问题

What do you think of Andrew —- There are some things that are not easyto ______ and his coldness is one
A:to alert the reader to thedwindling water supply
B:to explain industrial usesof water
C:to acquaint the readerwith water pollution problems
D:His not knowing how to
B:to explain industrial usesof water
C:to acquaint the readerwith water pollution problems
D:His not knowing how to
正确答案是: