题目

下列各组物理量中，都是矢量的是A．位移、时间、速度                             B．速度、质量、加速度C. 位移、加速度、速度                                     D．路程、时间、位移  答案：C解析:略 29、  Wealth and Health     Different weather makes people feel different．It influences(影响)health，intelligence(智力)and feelings．        In August，it is very hot and wet in the southern part of the United States．People there have heart trouble and other kinds of health problems during this month．In the Northeast and Middle West. it is very hot at some times and very cold at other times: People in these states have more heart trouble after the weather changes in February or March．     Weather can also influence intelligence．For example，in a 1983 report by scientists，IQ of a group of students were very high when a very strong wind came，but after the strong wind；their IQ was 10％ below．The wind can help people have more intelligence．Very hot weather，on the other hand．can make it lower．Students in many schools of the United States often get worse on exams in the hot months of the year(July and August)．     Weather also has a strong influence on people’s feelings．Winter may be a bad time to thin people．They usually feel cold during these months．They might feel unhappy during cold weather；But fat people may have a hard time in hot summer．At about 18℃，people become stronger．     Low air pressure(气压)may make people forgetful．People leave more begs on buses and in shops on low air pressure days．There is“good weather”for work and health．People feel best at temperature of about l 8℃．     Are you feeling sad，tried，forgetful，or unhappy today ?It may be the weather’s problem． 判断正(T)、误(F)： 1．Hot and wet weather have a bad effect oil health． 2．People may have higher intelligence when there is a rain．  3．Students in many schools of the United States often get better on exams in the cold months of the year． 4．Lower air pressure may make people remember thing easily． 5．In“good weather”of 18℃，people feel very sleepy．