—The room is so dirty, _____ we clean it?
—Of course.
| A．will | B．shall | C．would | D．do |
_____ matters most in learning English is enough practice.
| A．what | B．why | C．how | D．Which |
If I a quarrel with him yesterday, we together now.
| A．hadn’t had; would stay | B．haven’t had; would have stayed |
| C．didn’t have; would stay | D．hadn’t had; would have stayed |
It _____ have been Tom that parked the car here, as he is the only one with a car.
| A．may | B．can | C．must | D．should |
Though money, his parents managed to send him to university.
| A．lacked | B．lacking of | C．lacking | D．lacked in |
The flu is believed by viruses that like to reproduce in the cells inside the human nose and throat.
| A．causing | B．being caused | C．to be caused | D．to have caused |