题目内容
The girl had hardly rung the bell______the door was opened suddenly，and her friend rushed out to greet her.
A. before
B. until
C. as
D. since
________they decide which college to go to, students should research the admission procedures.
A. As
B. While
C. Until
D. Once
China is no longer ______ it was 30 years ago, ______ its economy didn’t develop well.
A. what; when B. that; which C. what; which D. which; that
After he retired from office, Rogers painting for a while, but soon lost interest.
A. took up B. saved up C. kept up D. drew up
