I believe the teacher's explanation will ________this puzzling problem.
| A．throw light on |
| B．come to light |
| C．see the light |
| D．make light of |
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 |
In order to find the missing child, villagers __________ all they can over the past five hours.
| A．did | B．do |
| C．had done | D．have been doing |