_________． according to the instructions，the medicine will work for your headache．
| A．To take | B．Taking |
| C．Taken | D．Take |
—I'm sorry, but I don't quite follow you. Did you say you wanted to return on September 20?
—Sorry, I __________ myself clear. We want to return on October 20.
| A．hadn't made | B．wouldn't make |
| C．don't make | D．haven't made |
I have to see the doctor because I __________ a lot lately.
| A．have been coughing | B．had coughed |
| C．coughed | D．cough |
When you are home, give a call to let me know you __________ safely.
| A．are arriving | B．have arrived |
| C．had arrived | D．will arrive |
Tom __________ in the library every night over the last three months.
| A．works | B．worked |
| C．has been working | D．had been working |
—I remember you were a talented pianist at college. Can you play the piano for me?
—Sorry, I __________ the piano for years.
| A．don't play | B．wasn't playing |
| C．haven't played | D．hadn't played |