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
Tom, together with his parents the yard when I saw him.
He was busy preparing his lessons, only _________ occasionally to have some tea.[ ]
The life we were used to ________since smart mobile phones rushed in.
Dad, would you please drive ______ —No hurry. We have enough time before the plane takes off.