在英语越来越重要的21世纪，学好英语成了大学生的首要目标。为帮助大学生更好地掌握英语知识，特提供以下文章：
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