That restaurant is extremely popular, ______ you may have to wait to get a seat.
| A．for | B．so |
| C．or | D．yet |
Up to now, thousands of red phone boxes, the old image of Britain, ________ due to mobile phones.
| A．removed | B．have removed |
| C．were removed | D．have been removed |
This is a promising company as its employees ________ to think outside the box and develop creative solutions.
| A．encourage | B．have encouraged |
| C．were encouraged | D．are encouraged |
I can't understand why he ________ so selfish. He isn't usually like that.
| A．was | B．had been |
| C．is | D．is being |
—How long have you been going to work on foot?
—Since last month when I ________ from a heart attack.
| A．recovered | B．have recovered |
| C．was recovering | D．would recover |
Allen has decided that he will be an engineer by the time he ________ twenty.
| A．had been | B．is going to be |
| C．will be | D．is |