问题补充:
The global warming is more and more serious, for which human beings .
A. are blaming
B. are to blame
C. are going to blame
D. are to be blamed
答案:
A. are blaming
(答案→)B. are to blame
C. are going to blame
D. are to be blamed
解析:考查短语。be to blame for 应受到责备。句意:全球变暖变得越来越严重了,人类应对此负责。