Sarah pretended to be cheerful, __________ nothing about the argument.
| A．says |
| B．said |
| C．to say |
| D．saying |
—If he ___________, he ________that food.
—Luckily he was sent to the hospital immediately.
| A． was warned; would not take | B．had been warned; would not have taken |
| C．would be warned; had not taken | D．would have been warned; had not taken |
When a pencil is partly in a glass of water, it looks as if it _______.
| A． breaks | B．has broken | C．were broken | D．had been broken |
One learns a language by making mistakes and _______ them.
| A． correct | B．correcting | C．corrects | D．to correct |
_____such heavy pollution already, it may now be too late to clean up the river.
| A． Having suffered | B．Suffering | C．To suffer | D．Suffered |
—Will you stay for lunch?
—Sorry, ____________. My brother is coming to see me.
| A． I mustn’t | B．I can’t | C．I needn’t | D．I won’t |