客户车内有空的纸巾盒或空的水瓶我们可以为其丢掉吗？

(9分)有同学利用如图所示的装置来验证力的平行四边形定则：在竖直木板上铺有白纸，固定两个光滑的滑轮A和B，将绳子打一个结点O，每个钩码的质量相等，当系统达到平衡时，根据钩码个数读出三根绳子的拉力，和，回答下列问题：

①改变钩码个数，实验不能完成的是( )

A．钩码的个数,

B．钩码的个数,

C．钩码的个数

D．钩码的个数,

②在拆下钩码和绳子前，正确并且最重要的一个步骤是（    ）

A.标记结点O的位置，并记录OA、OB、OC三段绳的方向

B.量出OA、OB、OC三段绳子的长度

C.用量角器量出三段绳子之间的夹角

D.用天平测出钩码的质量

③本实验采用的科学方法是（    ）

A.理想实验法    B.控制变量法

C.等效替代法    D.建立物理模型法

在西气东输工程的施工过程中，严格规定了28米宽的施工区域，尽量避免破坏地表植被，其主要目的是（　　）

A．保护脆弱的生态环境

B．促进新疆经济发展

C．降低施工成本

D．增加当地财政收入

  Arthur  Miller(1915-2005)is universally  recognized  as one of the greatest dramatists  of the 20^th  century. Miller`s father  had  moved to the USA from  Austria Hungary．Drawn like so many other by the“Great American  Dream”However, he experienced severe financial hardship when his family business was ruined in the Great Depression of the  earlv l930s.

Milles's most famous play, Death of a SaIesman, is a powerful attack on the American system.with its aggressive way of doing business and its insistence on money and social status as indicators of worth. In Willy Loman, the hero of the play, we see a man who has got into double with his worth. Willy is “burnt out” and in the cruel world of business there is no room for sentiment : if he can't do the work, then he is no good to his employer, the Wagner Company, and he must go. Willy is painfully aware of this, and at loss as to what to do with his lack of sucess. He refuses to face the fact that he has failed and kills himself in the end.

When it was first staged in 1949 ,the  play was greeted with enthusiastic revews,and it won the Tony Award for Best Play,the New York Drama Critics` Circle Award,and the Pulitzer Prize for Drama.It was the first play to win all three of these major awards.

Millerl died  of hear failure at his home in Roxbury,Connecticut,on the evening of February 10,2005,the 56th anniversary  of the first performance of Death of a Salesman on Broadway.

小题1:

Why did Arthur Miller' s father move to the USA?

A．He suffered from severe hunger in his home country.

B．He was attracted by the "Great American Dream.

C．He hoped to make his son a dramatist.

D．His family business failed.小题2:

The play Death of a Salesman

A．exposes the cruelty of the American business world

B．discusses the ways to get promoted in a company

C．talks about the business career of Arthur Miller

D．focuses on the skills in doing business小题3:

What can we learn about Willy Loman?

A．He treats his employer badly.

B．He runs the Wagner Company.

C．He is a victim of the American system.

D．He is regarded as a hero by his colleagues.小题4:

After it was first staged, Death of a Salesman

A．achieved huge success

B．won the first Tony Award

C．was warmly welcomed by salesmen

D．was severely attacked by dramatists小题5:

What is the text mainly about?

A．Arthur Miller and his family.

B．The awards Arthur Miller won.

C．The hardship Arthur Miller experienced.

D．Arthur Miller and his best-known play.

什么是I类手持电动工具？使用时应注意什么？

型号为200的滚动轴承的内径是（）

A、10mm

B、20mm

C、100m