问题

Tom looked upon the test as an obstacle _____ his classmates regarded it as a challenge
A:while
B:because
C:unless
D:if
B:because
C:unless
D:if
正确答案是:
同类题型
Ten minutes later,a bus ______ and everybody got on it.
Where _________ we go this weekend — Let’s go to the park together.
In my opinion, life in the twentyfirst century is much easier than ________.[ ]
It’s secret between us .Don’t tell anybody. —Sure ,.
___________ is known to everybody, the noon travels around the earth once every month.