如图为小球在水平面内做圆周运动的示意图,关于小球的受力情况,下列说法中正确的是(

题型:选择题

问题:

如图为小球在水平面内做圆周运动的示意图,关于小球的受力情况,下列说法中正确的是(  )

A.小球不受力

B.小球受平衡力

C.小球受非平衡力

D.小球只受重力

考点:物体运动状态的变化平衡力与平衡状态
题型:选择题

阅读理解

     Boys need friends, suffer when they don't believe they have any, and worry over the ups and downs of relationships. Many adults believe that somehow boys need friends less than girls do, in truth, though, no

boy is an island; boys value their friends throughout childhood and adolescence and are happier and

healthier when they have solid relationships with peers(同龄人).

     Despite the common belief that girls are better at relationships, most boys consider their friends a very

important part of their lives, and boys may actually be better at keeping friendships than girls are. A recent study of 10 to 15yearold boys and girls found that girls' friendships are actually more fragile. Girls tend to

say and do hurtful things to each other more frequently than boys, and girls are more hurt by the end of a

friendship.

     Boys are the living definition of the phrase "peer group"; they love games with rules, competition, and doing things together. Boys seem to enjoy, even need the opportunity to test themselves against others, and many lasting friendships begin in karate(空手道) class or on the basketball court. Competence and skill

are widely respected; being picked last for a team or left out altogether is an experience that can haunt

(萦绕心头) a boy for years.

     As boys mature, the friendship becomes even more important, and it frequently widens to include girls. During the teen years, friends can become the most important part of a boy's life-and a part in which his

parents are not included. The confusion of being a teenager leads boys to form close bonds with friends.

There is the sense for many boys that a friend is someone who is "always there for me", someone he can

trust. They may be partners in crime or partners in study, but the friendship of adolescent boys can run

surprisingly deep.

1. The common belief of adults is that boys________.

A. don't care about others as much as girls

B. don't value friendship as much as girls

C. have the same friendship as girls

D. have healthier friendship than girls

2. According to the text, boys' friendship________.

A. is usually built around active play

B. tends to be in small groups

C. can bear mutual hurt between friends

D. doesn't suffer from failure

3. The author mentions the study in the second paragraph to prove ________.

A. many people believe girls are better at relationships

B. most boys consider their friends very important

C. boys may be better at keeping friendships than girls

D. boys may be more active in a friendship

4. As a boy gets older, he tends to________.

A. widen his circle of friends to include different kinds of people

B. shift his focus from his friends to himself

C. leave his parents out of his friendship

D. be confused about what a friendship is

5. What's the best title for the text?

A. Friendships between Boys and Girls

B. Boys and Their Friendship

C. Childhood and Adolescent Friendship

D. Tips on Making Friends with Boys

题型:选择题

两仪

题型:选择题

下列说法不正确的选项组合是哪项
①1789年法国资产阶级革命取得胜利,制宪会议通过了著名的《 * * 宣言》,这是欧洲大陆上第一部成文宪法。②现阶段我国爱国统一战线包括两个联盟:一个是工人和农民的联盟;另一个是由以工人、农民、知识分子为主体的全体社会主义劳动者和拥护社会主义的爱国者所组成的联盟。③宪法是国家的总章程,调整的社会关系非常广泛,包括国家的一切组织和全体公民,体现了公共意志。④中华人民共和国的一切权利属于人民。人民代表大会制度是中华人民共和国的根本政治制度。⑤宪法的基本任务,是用法律的形式规定国家生活的主要原则。

A.①②③④

B.②③④⑤

C.②④⑤

D.①②③⑤

题型:选择题

下列有关证券发行的表述中,正确的一项是( )。

A.上市公司对发行股票所募资金,擅自改变招股说明书所列资金用途使用的,证券持有人可以按照发行价加算多算银行同期存款利息,要求上市公司返还

B.公开发行证券的发行人有权依法自主选择承销的证券公司,但应当报国务院证券监督管理机构批准

C.向社会公开发行的证券票面总值超过人民币50007元的,可以由承销团承销

D.证券的代销、包销期最长不得超过90日。

题型:选择题

往复式压缩机起动前盘车,要求至少:()。

A、0.5周;

B、1周;

C、2周。

更多题库