问题 选择题

以下集合为有限集的是(  )

A.由大于10的所有自然数组成的集合

B.平面内到一个定点O的距离等于定长l(l>0)的所有点P组成的集合

C.由24与30的所有公约数组成的集合

D.由24与30的所有公倍数组成的集合

答案

对于A:大于10的所有自然数:11、12、13…,一直到+∞,有无数个满足条件的自然数,所以A不合题意

对于B:满足题意点的轨迹是以点O为圆心,以l为半径的圆,即满足条件的点,是圆上的点,而圆上有无数个点,所以B不合题意

对于C:24与30的公约数有:1、2、3、6.有有限个,所以C满足题意

对于D::设m=240×n (n∈N+),则m都可以是24与30的公倍数,所以24与30的公倍数有无数个,D不合题意

故选C

阅读理解

阅读理解。

     Making Our Team Work Best

      Learning in school, we often work in small groups.But why? Is it necessary to work with others?

What if you feel comfortable doing a job by yourself ? In reality, however, after leaving school, you will

find out that almost all work in many fields is done in teams.

1.____

     Actually, a team is a group of individual people brought together in order to complete a task which

cannot be efficiently finished by any member of the group alone.The group may be temporary or it

may stay together for a long period.

2.____

      A type of team that we are familiar with are sports teams, which are made up of a certain numbers

of players.They work together to win a match.In fact, different numbers have different skills in a team.A team can only work well when all their members cooperate.The atmosphere in a team affects

the performance of the team, so the social relations within the team are important.

3.____

      Teams require leaders, and people who create ideas, who develop ideas, and people whose role is

to comment and help improve plans.People who identify problems and suggest solutions are needed

in a team, too.Every team member works in their most efficient way to make the whole team work

best.

4.____

      Regulations and rules help teams work well.But be careful.Working in a team, we have to take

into account how each individual member can work best.Some may work best on task alone; others

work best in groups.How the group task is divided depends on the personalities and abilities of the

individual in the group.

5.___

      In a dynamic (充满活力的) team, people with quite different personalities work well together.

Actually, their differences are the strength of the team.To make the best of working with our classmates, or to make our team work best, it is important to recognize the strengths and weaknesses of each individual of the group.

     To know someone's personality type and ability is to know a great deal about that individual person,

or to understand that person.To understand means that we can build strong relationship between

members of a team, and make the best use of each others' talents.

A.Knowing about Team Members

B.Functions of Rules and Regulations

C.Team Members and Their Roles

D.How a Team Works

E.A Sports Team

F.The Definition (定义) of a Team

单项选择题