-What's up? You look worried.
Well,I_____on the problem for 5 hours but I haven't got a single clue.
| A．have worked | B．worked |
| C．will work | D．have been working |
—Did you visit the famous cultural relics last month?
—No,we _________ it,but we spent too much time shopping.
| A．could have visited |
| B．must have visited |
| C．can’t have visited |
| D．shouldn’t have visited |
Never in my wildest dreams _________ lead to a career in the NBA,which has allowed me to give back to my people in Africa.
| A．I thought the chance would |
| B．I thought would the chance |
| C．did I think the chance would |
| D．did I think would the chance |
We didn’t know where it was ________ the other tourists in our group stayed for the night until the tsunami was over.
| A．that | B．which | C．when | D．why |
—________ one and a half days enough for the painting to be finished?
—I don’t think it’s enough and only after _________ go on with it.
| A．Is;will be recover he can | B．Are;he recovers can he |
| C．Are;he recovers he can | D．Is;he recovers can he |
Computers and the advantage _________ gave us _________ being made better use of presently.
| A．that;is | B．they;are |
| C．it;was | D．which;were |