----Why is he feeling down today?
----Because the suggestion he _______ has been turned down.
| A．put away | B．put up |
| C．put down | D．put forward |
— Mummy, I have broken my train.
一I told you so. You _______ on it.
| A．mustn't have ridden | B．couldn't ride |
| C．shouldn't have ridden | D．needn't ride |
You can't imagine that a top student ______ have failed in the college entrance examination.
| A．might | B．need | C．should | D．would |
Thank you for giving me a hand. I ______ in the experiment without your valuable help.
| A．have failed | B．will fail | C．would have failed | D．must have failed |
This cake is very sweet. You _____ a lot of sugar in it.
| A．should put | B．could have put | C．might put | D．must have put |
He paid for a seat, when he ______ have entered free.
| A．could | B．would | C．must | D．need |