问题 填空题

静止在水平面上质量为50kg的物体,与水平面间的动摩擦因数为0.2,当作用在该物体上的水平拉力为30N时,它受的是____________摩擦力,其大小为____________N。当作用力增大到110N时,物体刚要开始滑动,则物体与地面间的最大静摩擦力为____________N,物体滑动后欲使物体做匀速直线运动,则应对它施加____________N的拉力。(取g=10N/kg)

答案

静,30,110,100

完形填空

Friends play an important part in our lives, and although we may take the fact of friendship for granted, we often don’t clearly understand how we make friends. While we get on well with a number of people,      小题1:   .

Moreover, a great many relationships come under the general term “friendship”. In all cases, two people like one another and enjoy being together, but beyond that, the degree of closeness between them and the reasons for their interest in each other change greatly.

At the beginning, much depends on how people meet, and on good first impressions. As we get to know people,    小题2:   . Although these factors are not of the greatest importance, it is more difficult to have a good relationship with people when there is a big difference in age and background.

Then,   小题3:  . Friends will stand closer together and will spend more time looking at each other than ordinary friends. Smiles and soft voices also express friendliness, and it is because they may give the wrong signals that shy people often have difficulty making friends. A friendly look with a wrong facial expression can turn into an unfriendly stare, and nervousness may be wrongly understood as unfriendliness.

Some relationships are a result of argument and discussion, but it is usual for close friends to have the same ideas and beliefs, the same opinion and interests. The more closely involved people become, the more they depend on each other. And    小题4:   . Equally, friends have to learn to make allowances for each other, to put up with annoying habits, and to accept differences in opinion.

In contrast with marriage,   小题5:   . But the support and understanding that results from shared experiences and affections does seem to create a close and lasting relationship.

A.we are usually friends with only a few

B.many factors can affect friendship and relationship

C.people want to do friends favors and hate to let them down

D.argument and discussion can improve personal relationshipsE. we consider things like age, race, looks, economic and social status, etc

F. we pay attention to actual behavior, facial expression, and the way a person speaks

G. there are no friendship ceremonies to strengthen the relationship between two people

单项选择题