_____in the sports world，a sportsman needs to train constantly to keep himself in best condition．
| A．Survive | B．Surviving | C．To survive | D．Survived |
_______ my teachers’ help, I wouldn’t have succeeded.
| A．Thanks to | B．Owing to | C．But for | D．As to |
Not until _______ 18 years old _______ a right to vote.
| A．have you reached; can you have | B．have you reached; you can have |
| C．you have reached; can you have | D．you have reached; you can have |
--Who is the person talking with you just now?
-- Well, if you ______ know, his name is David.
| A．may | B．can | C．must | D．shall |
Alice， _______ university teacher from Australia, teaches me ______ English in her spare time.
| A．an; / | B．a; the | C．an; the | D．a; / |
It is morning _____ we have four classes, not afternoon.
| A．when | B．which | C．that | D．why |