问题 问答题

在图中,画出在斜面上匀速上滑的物体A所受到的重力和摩擦力的示意图(说明:重力大于摩擦力)

答案

根据题设要求画出重力和摩擦力的示意图,力的示意图就是粗略作出力的三要素的过程.根据重力的方向竖直向下,摩擦力的方向平行于斜面向下,且重力的大小大于摩擦力的大小,根据力的示意图的作图步骤:一画简图二定点,三画线,四画尖,五把力的符号标尖边.则有:

材料题
单项选择题

A recent poll indicated that half the teenagers in the United States believe that communication between them and their parents is (1) and further that one of the prime causes of this gap is (2) listening behavior. As a(an) (3) in point, one parent believed that her daughter had a severe (4) problem. She was so (5) that she took her to an audiologist to have her ear tested. The audiologist carefully tested both ears and reported back to the parent:"There’s nothing wrong with her hearing. She’s just (6) you out. "

A leading cause of the (7) divorce rate (more than half of all marriages end in divorce) is the failure of husbands and wives to (8) effectively. They don’t listen to each other. Neither person (9) to the actual message sent by the other.

In (10) fashion, political scientists report that a growing number of people believe that their elected and (11) officials are out of (12) with the constituents they are supposedly (13) Why Because they don’t believe that they listen to them. In fact, it seems that sometimes our politicians don’t even listen to themselves. The following is a true story: At a national (14) conference held in Albuquerque some years ago, then Senator Joseph Montoya was (15) a copy of a press release by a press aide shortly before he got up before the audience to (16) a speech. When he rose to speak, (17) the horror of the press aide and the (18) of his audience, Montoya began reading the press release, not his speech. He began, "For immediate release. Senator Joseph M. Montoya, Democrat of New Mexico, last night told the National... " Montoya read the entire six page release, (19) with the statement that he "was repeatedly (20) by applause.

1()

A.scarce

B.little

C.rare

D.poor