663. “X” _______　 for the unknown quantity.

A. puts　　 B. stands　　　 C. sits　　　　 D. goes

662. By the time he gets home, his aunt ______ for Puerto Rico .

A. will leave　 B. leaves　　 C. will have left　 D. left

661. By the time he retires, Professor Baker ____ for almost forty years.

A. will teach　　　　　　 B. has taught

C. will have taught　　　 D. will be teaching

660. – How did you pay these workers?

　 --- Well, as a rule, they were paid ________.

A. by an hour　　　　 B. by the hour

C. by hours　　　　　 D. by a hour

ABBDA　 AABCB　 DADDB　 CBDCB

659. – How can I help you the most?

　 --- __________.

A. For you to stay　　　　　　 B. To stay

C. By staying　　　　　　　　 D. With your staying

658. My roommate lost a lot of weight ______ every day.

A. to exercise　　　　　 B. for exercise

C. for exercising　　 　　　D. by exercising

657. – Is she older than you?

　 --- Yes, she is older than _________two years.

A. me for　　 B. I am by　　　 C. I for　　 D. me by

656. – Did you feed the baby milk?

　 --- No, he can ________.

A. feed for himself　　　　　 B. feed by himself

C. eat by himself　　　　　　 D. eat for himself

655. Legal tender is any type of money that must, _______, be accepted in a payment of a debt.

A. law　　　 B. by law　　 C. its law　　　　 D. which law

654. The subject of these lectures _______ by the lecture committee.

A. announces　　　　　　　 B. have been

C. announced　　　　　　　 D. has been announced