A. of B. to C. up D. about
A. that today few people ever encounter quicksand B. that quicksand is still common in many parts of the country C. that quicksand cannot be detected by the eye alone D. expressed by none of the above
A. why colour affects humans B. colour and manufacturers C. colour and traffic accidents D. how colours influence human feelings
A. farmers B. supervisors C. weather D. war
A. difficult to produce in large quantities B. susceptible to many parasites(寄生虫) C. essential to the health of the country D. expensive to gather and transport
A. Control. B. Investigate. C. Finance. D. Reinforce.
A. installed B. fastened C. connected D. held
A. at once B. at first C. at best D. at least
A. believable pictures B. diverse subject matters C. a simple and direct explanation D. a number of causally linked events
A. effects of boredom on people's life and work B. various ways to conquer the feeling of boredom C. studies of possible reasons why people get bored D. the importance of scientific research into boredom