[单项选择]Most cloud formations occur when air masses of different temperatures collide.


A. touch
B. smash
C. bump
D. clash

[单项选择]What impressed the author most when he went to watch the lions in the Gir Forest


A. The lions were on the brink of extinction.
B. They were suffering from a fatal disease.
C. They allowed him to see their vitality and charm at close quarters.
D. Mother lion and her cub shared a deer.

[单项选择]Full employment is said to occur when:（）
A. the natural rate of unemployment equals zero.
B. the number employed divided by the number in the labor force is less then 5.0 percent.
C. cyclical unemployment equals zero.

[单项选择]Full moons occur when ______.


A. the moon is between the sun and the Earth
B. the Earth is between the moon and the sun
C. the sun is between the Earth and the moon
D. the side of the moon facing the Earth is dark

[单项选择]When did this event occur


A. In the late afternoon.
B. In the early afternoon.
C. In the evening.
D. In the mornin

[单项选择]When murders and terrorist attacks occur the police ______.


A. prefer to wait for the criminal to give himself away
B. spend a lot of effort on trying to track down their man
C. try to make a quick arrest in order to keep up their reputation
D. usually fail to produce results

[单项选择]

Personal interviewing is most effective when all the people to be interviewed are located in a relatively small geographical area. Otherwise, the time and expense spent in travelling from one person to another makes this type of interviewing economically impractical. Personal inter viewing is usually used when the information needed is too complex to be gathered by another technique. For example, a problem being studied may require the interviewer to probe beyond the more superficial answers that might be obtained with another method.
It is sometimes assumed that personal interviewing is the most accurate of all survey re search techniques. Although personal interviewing may be accurate in many cases, human errors may prevent a researcher from obtaining valid results. Questions perceived by the interview wee as an invasion of privacy or threatening in any way will probably produce false of partially true answers. Also, since the interviewer must interpret the respo
A. the interviewer can ask the interviewee questions again in different ways
B. the interviewer can ask the interviewee some personal questions
C. the initial question do not produce the information desired
D. no one is present to clarify questions