4．(1)用游标为50分度的游标卡尺测量某工件的长度时，示数如图实－5－21所示，则测量结果应该读作________mm.

图实－5－21

(2)用螺旋测微器测圆柱体的直径时，示数如图实－5－22所示，此示数为________mm.

图实－5－22

答案：(1)10.40　(2)2.720

3．(2008·全国卷Ⅱ)某同学用螺旋测微器测量一铜丝的直径，测微器的示数如图实－5－20所示，该铜丝的直径为________mm.

图实－5－20

解析：螺旋测微器固定刻度部分读数为4.5 mm，可动刻度部分读数为0.093 mm，所以所测铜丝直径为4.593 mm.

答案：4.592-4.594

2．将图实－5－19所示的螺旋测微器的读数写出来．

图实－5－19

甲．______mm　　　乙．______cm

解析；先读出固定尺上的读数，再读出可动尺上的读数．

甲.8 mm+47.7×0.01 mm＝8.477 mm.

乙.6.5 mm+7.8×0.01 mm＝6.578 mm＝0.6578 cm.

答案：8.476　0.6578

1．在“探究决定导线电阻的因素”的实验中，以下操作中错误的是　　　　　 (　)

A．用米尺测量金属丝的全长，且测量三次，算出其平均值，然后再将金属丝接入

电路中

B．用螺旋测微器在金属丝三个不同部位各测量一次直径，算出其平均值

C．用伏安法测电阻时采用电流表内接法，多次测量后算出平均值

D．实验中应保持金属丝的温度不变

解析：实验中应测量出金属丝接入电路中的有效长度，而不是全长；金属丝的电阻很小，与电压表内阻相差很大，使金属丝与电压表并联，电压表对它分流作用很小，应采用电流表外接法．故A、C操作错误．

答案：AC

20.According to Fries and Crapo sound health choices should be based on ____.

A)personal decisions B)society’s laws

19.To knowingly allow oneself to pursue unhealthy habits is compared by Fries and Crapo to ____.

A)improving the quality of one’s life

B)limiting one’s personal health choice

C)deliberately ending one’s life

D)breaking the rules of social behavior

18.Sound personal health choice is often difficult to make because ____. 　

A)current medical knowledge is still insufficient

B)there are many factors influencing our decisions

C)few people are willing to trade the quality of life for the quantity of life

D)people are usually influenced by the behavior of their friends

17.To “live a completely sedentary life?style”(L7,Para.1)in the passage means____.

A)to “live an inactive life”

B)to “live a decent life”

C)to “live a life with complete freedom”

D)to “live a life of vice”

16.The concept of personal choice concerning health is important because ____.

A)personal health choice help cure most illness

B)it helps raise the level of our medical knowledge

C)it is essential to personal freedom in American society

D)wrong decisions could lead to poor health

15.This passage is mainly concerned with ____.

A)whether language proficiency or work abuility counts in job interviews

B)how to avoid awkward situation in a job interview in HongKong

C)the language used in a job interview with both Chinese and expatriate panel members

D)the sensible procedure of getting on with an interview where the Chinese interviewee’s English is to be tested

D

The concept of personal choice in relation to health behaviors is an important one. An estimated 90 percent of all illnesses may be preventable if individuals would make sound personal health choice and do not like to see it restricted when it is within the legal and moral boundaries of society.The structure of American society allows us to make almost all our own personal decisions that may concern our health.If we so desire,we can smoke,drink excessively,refuse to wear seat belts,eat whatever foods we want,and live a completely sedentary life style without any exercise.The freedom to make such personal decisions is a fundamental aspect of our society,although the wisdom of these decisions can be questioned. Personal choices relative to health often cause a difficulty. As one example, a teenager may know the facts relative to smoking cigarettes and health but may be pressured by friends into believing it is the socially accepted thing to do.

A multitude of factors,both inherited and environmental,influence the development of health?related behaviors,and it is beyond the scope of this text to discuss all these factors as they may affect any given individual.However,the decision to adopt a particular health?related behavior is usually one of personal choices.There are healthy choices and there are unhealthy choices.In discussing the morals of personal choice,Fries and Grapo drew a comparison.They suggest that to knowingly give onself over to a behavior that has a statistical probability of shortening life is similar to attempting suicide.Thus,for those individuals who are interested in preserving both the quality and quantity of life,personal health choices should reflect those behaviors that are associated with a statistical probability of increased vitality and longevity.