如图所示，在水平桌面上叠放着木块P和Q，水平力F推动两个木块做匀速直线运动，下列

东欧剧变、苏联解体的实质是

A．市场经济体制确立

B．高度集权的管理体制崩溃

C．政治版图发生重大变化

D．社会制度发生改变

Do you want to do well in exams? Sometimes your knowledge is not enough, you also need good strategies. Here are some for you. 

Before you answer the questions, if you feel a little nervous, take a few deep breaths to help you relax.

Always read the question carefully and make sure that you understand it. Read it a few times if possible.

Find out how much each question is worth or how many points you need. If it asks to give one answer, only write one.

If there is a difficult question, don’t worry. Go on to the next question and come back to it if you have time later.

Try not to 1eave questions unanswered when you finish the text. Sometimes a guess may get you points.

When you finish, go back and check your answers. You will need to check your writing for spelling mistakes.

小题1:From the passage, we know we can            to help ourselves relax if we feel a little nervous.

A．tell ourselves not to be nervous

B．ask the teacher for help

C．go out for a walk

D．take a few deep breaths小题2:To make sure we understand the questions, we had better             .

A．read it fast

B．read it till we finish it

C．read it a few times if possible

D．read it slowly小题3:When we finish answering all the questions, we need to      

A．hand in at once

B．check spelling mistakes

C．worry about our points

D．check with classmates小题4:The underlined word "strategies" in the passage means       

A．策略

B．思维

C．途径

D．智慧小题5:Which of the following is NOT RIGHT according to the passage?

A．Find out how many points we need or how much each question worths.

B．Try not to leave questions unanswered when we finish the text.

C．If it asks to give one answer, we'd better write more.

D．Sometimes we should guess the answers to get points.

(二)
甲公司依法取得15亩蔬菜生产基地和城市规划区内20亩国有土地的土地使用权，用于开发商品房和经济适用住房，并委托某房地产估价机构对被拆迁房屋的市场价格进行了评估。开发建设过程中，甲公司依法取得商品房预售许可证后，委托乙公司代理预(销)售商品房。委托协议签订后，乙公司在媒体发布商品房预售广告，并协助甲公司为部分购房者办理抵押贷款手续。该小区全部竣工后，购房者陈某对所购商品房面积提出疑问，乙公司的销售人员进行了解释。甲公司按规定与购房者各自缴纳税费后，为购房者办理了房屋权属登记手续。

陈某购买商品房应缴纳的税为( )。

A．契税

B．营业税

C．城市维护建设税

D．印花税

胚胎发育过程中，因病毒或药物作用而易致先天性发育异常的时期为（）

A.受精后1～2周

B.受精后3～4周

C.受精后4～8周

D.受精后8～12周

E.受精后12周以后

简述汽车产品常见的促销方式。