—So hard _____ in the past few months that he has made great progress in English.
—I can see that; only a few mistakes _____ in the exam.
| A．has he worked; did he make | B．he has worked; did he make |
| C．he has worked; he made | D．has he worked; he made |
Though we don’t know what was discussed, yet we can feel the topic_____.
| A．had changed | B．will change | C．was changed | D．has been changed |
The moment I got home, I found I_____my jacket on the playground.
| A．had left | B．left | C．have left | D．was leaving |
The wet weather will continue tomorrow when a cold front ______ to arrive.
| A．is expected | B．is expecting | C．expects | D．will be expected |
—Have you known Dr. Jackson for a long time?
—Yes, since she________ the Chinese Society.
| A．has joined | B．joins | C．had joined | D．joined |
So far this year we ______ a fall in house prices by between 5 and 10 percent.
| A．saw | B．see | C．had seen | D．have seen |