一、单项选择（20分）
1. Thanks to the Party’s opening and reform policy, people in China are ______ than they were thirty years ago.
A. well off B. much better off C. more better off D. quite better off
2. Scientists are convinced ________ the positive effect of laughter _______ physical and mental health.
A. of; at B. by; in C. of; on D. on; at
3. I saw Tom _______into the classroom without _________.
A. slide; found B. sliding; find C. to slide; being found D. sliding; being found
4. Jack was ______ failure as a leader, but he achieved _______ great success in writing.
A. a; a B. a; / C. /; a D. /; /
5. My brother can’t attend the party ______ at Tom’s house at present, because he is preparing for his examination.
