1.We mustn’t relax our vigilance___.
　　A in the least
　　B at least
　　C at most
　　D in the end
　　
2. During the reading lesson, the teacher asked the students to read a few __ from the novel.　　
　　A pieces
　　B essays
　　C fragments
　　D extracts
　　
3. But they aslo __ beyond the individual places and consider the earth as a whole.　　
　　A pass
　　B reach
　　C go
　　 D set
　　
4. How human beings and their environment act __ each other.　　
　　A upon
 　　B for
　　C as
　　D to
　　
5. The mere fact __ most people believe nuclear war would be madness does not mean that it will not occur.
　　 A what
　　 B which
　　 C that
 　　 D why