If better use is ________ your spare time，you’ll make good progress in doing your business.
A. spent B. made of C. used for D. taken
It is believed _______ he has gone to Shanghai. The problem is ________ we can’t get in touch with him.
A．when; that B．that; that C．that; whether D．不填；不填
____ the 1990s, the number of antelopes had fallen to about 50,000.
A. During B. Since C. By D. Over
I'll never forget the day _______ I bought my own guitar with my own money.
A. where B. on which C. on when D. that
--Are you sure to help me find____________ bed for my new house?
--Of course, but not now. I'm heading, for____________ bed and a good sleep.
A. a, a B. a, 不填 C. the, a D. a, the
The old couple married for 40 years and never once____ with each other.
A. they had quarreled. B. they have quarreled
C. have they quarreled D. had they quarreled.
