—Did you visit the famous museum?
—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 |
The UN officials say it could be many weeks and even months ____ a deal is reached．
| A．before | B．after | C．when | D．as |
Either the ways or the time ____ yet, but you may ask the headmaster for some information．
| A．isn’t decided | B．hasn’t decided | C．aren’t decided | D．haven’t decided |
The purse found on the playground matches the ____ by Mary, so it must be hers．
| A．direction | B．description | C．expression | D．instruction |
—Quite a lot of students failed in the math exam．
—Exactly．It is ____ their abilities．
| A．within | B．over | C．against | D．beyond |
—Those scientists invented a robot to care for kids!
—It’s not surprising．They ____ wonders all the time．
| A．worked | B．were working | C．work | D．have been working |