______ he has made a decision, it is not easy for you to make him change his mind.
| A．Though | B．Unless | C．Until | D．Once |
Having received___________ training of the MS. Company, he was offered important position in management.
| A．the;an | B．不填;an | C．the;不填 | D．a;a |
He must have attended the meeting yesterday,___________ he?
| A．didn't | B．mustn't | C．needn't | D．hasn't |
I was really too busy with my homework and I couldn't help ____________
housework.
| A．doing | B．do | C．did | D．done |
Mary is one of the brightest students who_________ from New York University.
| A．is graduated | B．have graduated |
| C．has graduated | D．are graduated |
Mary is short__________ her brother is very tall.
| A．still | B．nor | C．while | D．when |