Mary went to the box office at lunch time, but all the tickets ____out. 
#104851
A
would sell
B
had sold
C
have sold
D
was selling
推荐题目
The milk must be preserved at this temperature until it ____.
#101024
A
will process
B
is processed
C
has processed
D
had been processed
 Don’t leave the chairs about, or you may ______ them at night.
#99797
A
take over
B
turn over
C
come over
D
trip over