He pretended _______ a book when his mother entered the room.
| A．to read | B．to have read | C．reading | D．to be reading |
30. How long do you think it will be _____ we can find a new water source?
| A．after | B．before | C．when | D．Since |
29. High up in the mountains _____ a quiet small village, with only 20 households.
| A．surrounds | B．locates | C．lies | D．Lays |
28. A heavy snow promises a good harvest, _____ is often the case.
| A．where | B．as | C．that | D．What |
27. After his wife died, he kept himself _____ from other people and the outside world,
| A．set off | B．cut off | C．put off | D．taken off |
26. — Why is little Jimmy so naughty today?
— He is bored, so he _____ a little silly.
| A．will be | B．is being | C．had been | D．would be |