下套管刮削器，在油层射孔井段上下反复刮削3次后，刮削至油层以20m。

某上市公司2011年的年度财务报告于2012年2月10日编制完成，注册会计师完成年度财务报告审计工作并签署审计报告的日期为2012年4月5日，董事会批准财务报告对外公布的日期为2012年4月6日，财务报告实际对外公布的日期为2012年4月18日，股东大会召开日期为2012年4月22日。则该上市公司2011年度资产负债表日后事项涵盖的期间为()。

A.2012年1月1日至2012年2月10日

B.2012年1月1日至2012年4月6日

C.2012年1月1日至2012年4月18日

D.2012年1月1日至2012年4月22日

下列说法可充分说明P(g)+Q(g)  S(g)+R(g)在恒温、恒容密闭容器中的反应已达平衡的是 [ ]

A．容器里P、Q、R、S四种物质共存

B．容器里Q、R的体积分数不再改变

C．容器内气体压强、密度不随时间变化

D．单位时间内同时生成n mol P和n mol S

为除去农作物的某种害虫而引入其天敌蜘蛛，一段时间后，对两个种群进行调查，得出如图所示的结果(图中两条曲线分别表示它们的数量变化)。有关叙述正确的是

A．在a～b期间，若同时引入害虫的另一种天敌螳螂，蜘蛛的数量将增加更快

B．在b～c期间，造成蜘蛛数量减少的原因是蜘蛛的食物不足

C．在c～d期间两个种群数量保持相对稳定的原因是发生了种间互助

D．害虫数量减少可导致蜘蛛数量增加

整群抽样的优缺点是什么？

Japanese people,who never miss a chance to be photographed,were lining up to get their pictures on a postage stamp．Vanity（虚荣）stamps with personal photographs went on sale for the first time in Japan as part of an international postage stamp exhibition．The customer’s photo was taken with a digital camera and then printed on stamp sheets,a process that takes about five minutes．Sold in a sheet of 10 stamps for $8．80,little more than the cost of lunch in Tokyo,each stamp printed a different scene from a traditional painting along with the photo．

The stamps can be used normally to mail a letter,and postal officials hope they will help encourage interest in letter writing in the Internet age．“Certainly e-mail is a useful method of communication,but letters are fun in a different way,”said Hatsumi Shimizu an official in the Post Ministry．“We want to show young people that letters can be fun too．”[

While similar stamp sheets appeared in Australia in 1999 and are now sold in some nations and territories,Japan’s fondness for commemorative photos is likely to make them especially popular here．Indeed,officials had prepared 1 000 sheets but they were sold out in less than 30 minutes．Although the stamps are currently only available as a special service during the exhibition,postal officials said they may start selling them on a regular basis in the future．

小题1:The best title of this passage might be______．

A．Never Miss a Chance to be Photographed

B．Your Own Face on a Postage Stamp

C．First Japanese Postage Stamps with a Photo

D．Letters are as Fun as E-mails小题2:By saying“little more than the cost of lunch in Tokyo”,the author really means______．

A．this service is not very expensive

B．the cost of this service is very high

C．food in Tokyo is very dear

D．$8．80 is a very small amount of money小题3:The purpose of this activity is______．

A．to make the international postage stamp exhibition more interesting

B．to make more stamps for normal use

C．to draw interest in writing letters

D．to satisfy Japan’s fondness of commemorative photos小题4:Which of the following is true according to the passage?

A．Japanese people like to take photos．

B．This kind of stamps must be used to mail letters．

C．Japanese people can get this kind of stamps easily after the stamp exhibition．

D．This service is more popular in Japan than in other places．