Every possible means _______ to prevent the crash , but the computer doesn’t still work．
| A．is used | B．are used |
| C．has been used | D．have been used |
----I was riding along the street and all of a sudden, a car cut in and knocked me down.
------You can never be _____careful in the street.
| A．much | B．very | C．so | D．too |
In the past few years, My Heart Will Go On was a popular song among young people, _____were often heard singing it at parties．
| A．who | B．which | C．they | D．that |
---I regret _____you John has been fired．
---I can hardly believe my ears．He’s such a fine worker．
| A．telling | B．having told | C．to tell | D．to have told |
— 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 |
But when I got _______ the town ought to have been, all I found was a gas station．
| A．where | B．which | C．what | D．that |