— We did not see him at the lecture yesterday．
— You _______ him, since I went to an international conference with him．
| A．mustn’t have seen | B．can’t have seen |
| C．couldn’t see | D．needn’t have seen |
With a lot of tough problems, the pilot was still calm, cool and collective under pressure.
| A．solve | B．solved | C．solving | D．to solve |
left the door unlocked must be held responsible for the accident.
| A．Whomever | B．Whoever | C．Whatever | D．Whenever |
If we use the new recycling method, a large number of trees.
| A．are saved | B．will save | C．will be saved | D．have saved |
．She is fed up with sharing a house with others; , she is looking for her own flat.
| A．moreover | B．otherwise | C．however | D．therefore |
—What’s wrong with your ipad? The soundis not clear.
—Yes. It has been broken for some time.
| A．come out | B．coming out | C．to come out | D．came out |