Looking at my mother's ___________ face, I regretted not having told her my whereabouts on the phone.
| A．worrying | B．worried | C．anxioused | D．satisfied |
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 |
Helen ______ go on the trip with us, but she isn’t quite sure yet.
| A．shall | B．must | C．may | D．can |