Mr. Smith always ________ short stories，but he ________ a TV play these days.
| A．is writing；is writing | B．is writing；writes |
| C．writes；is writing | D．writes；writes |
He told us that he was tired and thirsty because he ________ in the desert for days.
| A．walked | B．has walked |
| C．had walked | D．would walk |
My mother ________ as an architect since she graduated from Tongji University.
| A．worked | B．has worked |
| C．had worked | D．is working |
According to the timetable, the plane ________ for Los Angeles at 5 in the afternoon.
A. would leave B. left
C leaves D. has left
I ________ hear the news very clearly since the noise outside is so loud.
| A．mustn’t | B．can’t |
| C．needn’t | D．may not |
Jenny enjoys reading and spends a lot of money on books __she is not rich.
| A．if | B．when |
| C．because | D．though |