第二部分选择填空（共20小题；每小题1分，满分20分）
21.—Have you seen _______ pen? I left it here this morning.
—Is it _______ black one? I think I saw it somewhere.
| A．a, the | B．the, the | C．the, a | D．a, a |
After she considered the problem, she got a tall box to stand ________.
| A． on | B．up | C．above | D．by |
The changes in the city will cost quite a lot, ___________they will save us money in the long run.
| A． or | B．since | C．for | D．but |
—I hear Jane has gone to the Holy Island for her holiday.
—Oh, how nice! Do you know when she______________?
| A． was leaving | B． had left | C． has left | D． left |
Selecting a mobile phone for personal use is no easy task because technology____ so rapidly.
| A． is changing | B．has changed | C．will have changed | D．will change |
It was __________ back home after the experiment.
| A． not until midnight did he go | B． until midnight that he didn’t go |
| C． not until midnight that he went | D． until midnight when he didn’t go |