______ professional violinsit practises for several hours a day, but ______ violinist has his own way of playing the Beethoven concert.
| A．Each；every | B．Every；each | C．All；every | D．Either；every |
John, look at the time. ___________ you play the piano at such a late hour?
| A．Must | B．Can | C．May | D．Need |
—May I smoke here ?
—If you ____, choose a seat in the smoking section.
| A．should | B．could | C．may | D．must |
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 |
— The woman biologist stayed in Africa studying wild animals for 13 years before she returned.
— Oh, dear ! She ______ a lot of difficulties !
| A．may go through | B．might go through |
| C．ought to have gone through | D．must have gone through |
Helen ______ go on the trip with us, but she isn’t quite sure yet.
| A．shall | B．must | C．may | D．can |