---where’s Mom?
-----She’s in the kitchen. She _____the housework all morning
| A．is doing | B．was doing |
| C．did | D．has been doing |
________ many times, but he still could not understand it.
| A．Having been told | B．Tough he had been told |
| C．He was told | D．Having told |
Faced with a bill for $ 10,000,_________.
| A．John had to take an extra job | B．the boss has given John an extra job |
| C．an extra job has been taken | D．an extra job has been given to John |
-----My room gets very cold at night.
-----_________________.
| A．So is mine | B．So mine is | C．So does mine | D．So mine does |
At the end of the meeting, it was announced that an agreement ________.
| A．has been reached | B．had been reached | C．has made | D．signed |
----She looks happy. She _______ have passed the exam.
-----I guess so. It is not difficult after all.
| A．should | B．could | C．must | D．might |