问题补充:
It is human activities on the earth that are to global warming.
A. be blamed for
B. blame for
C. take charge of
D. be responsible with
答案:
A. be blamed for
(答案→)B. blame for
C. take charge of
D. be responsible with
解析:考查固定结构。Be to blame for应受责备,为……负责。所以选B。