—Only once.

A. does; go B. did; go

C. has; gone D. has; been

A. to, it in B. to, it up

C. for, it in D. for, it up

A. fall down B. fall off

C. fall over D. fall ill

【题目】My mother is ________ English teacher in ________ university.
A.an; an
B.an; a
C.a; an
D.a; a

—— Don’t you think we should leave a bit earlier to ___ the rush hour?

A. change B. circle C. dismiss D. avoid

— ! He learned singing by himself.

A. Everybody B. Somebody C. Nobody