问题 选择题

两端封闭的均匀直玻璃管竖直放置,内用高h的汞柱把管内空气分为上下两部分,静止时两段空气柱的长均为L,上端空气柱压强为p1=2ρgh(ρ为水银的密度)。当玻璃管随升降机一起在竖直方向上做匀变速运动时,稳定后发现上端空气柱长减为2L/3。则下列说法中正确的是(         )

A.稳定后上段空气柱的压强大于2ρgh

B.稳定后下段空气柱的压强小于3ρgh

C.升降机一定在加速上升

D.升降机可能在加速下降

答案

ABD

题目分析:据题意,当玻璃管静止时,汞柱也处于静止状态,则上部分空气柱的压强为p1=2ρgh,下部分空气柱压强为p2=3ρgh;当玻璃管随升降机一起做匀变速运动时,由于上部分空气柱被压缩,据PV/T=K可知,一定质量的气体当温度不变时,上部分空气柱体积减小则压强增大,所以A选项正确;而下部分空气柱由于体积增大而压强减小,B选项正确;由于上部分空气柱被压缩,说明汞柱加速度向下,汞柱处于失重状态,则升降机可能加速下降,也肯能减速上升,所以C选项错误;而D选项正确。

不定项选择

案例二  (一)资料  2010年4月,某审计组对乙公司2009年度财务收支进行了审计。有关情况和资料如下:  1.乙公司共生产A、B两种产品,其中A产品在国内销售,B产品销往国外。  2.审计人员在对该公司生产与存货业务循环内部控制进行调查时了解到:生产车间按生产计划部门签发的生产通知单组织生产;产品入库前,质检部门对产品质量进行检验;仓储部门登记存货明细账;由独立于仓储部门之外的其他部门人员定期对存货进行盘点。  3.审计人员在对相关内部控制进行了解的基础上,采取了如下审计程序:抽查3个月的产品盘点记录,查看盘点范围和组织方式;比较近几年各产品生产成本总额及单位生产成本,分析有无异常波动;抽取部分领料凭证,查看有关记录是否完整,手续是否齐备;抽取部分产品盘亏记录,检查其账务处理是否经被授权人批准。  4.乙公司11月产品盘点记录显示,A产品发生少量盘亏,经查系计量误差所致。该公司将盘亏产品损失记人“管理费用”。  5.2009年乙公司将生产工人、车间管理人员、管理部门人员和销售部门人员工资全部计人产品成本。  6.受国际金融危机影响,B产品销售价格持续下跌,2009年12月31日,库存产品B账面价值为1500万元,可变现净值为900万元;A产品受国内扩大内需政策的影响,销售价格稳步上升,2009年12月31日,库存产品A账面价值为I 200万元,可变现净值为l 500万元。该公司一直未计提存货跌价准备。  (二)要求:根据上述资料,为下列问题从备选答案中选出正确的答案。

针对“资料5”,审计人员认为乙公司的做法:

A.正确

B.不正确,只有生产工人的工资才能计入产品成本

C.不正确,只有生产工人和车间管理人员的工资才能计人产品成本

D.不正确,只有生产工人、车间管理人员和管理部门人员的工资才能计人产品成本

单项选择题

Americans usually consider themselves a friendly people. Their friendships, however, tend to be shorter and more casual than friendships among people from other cultures. It is not uncommon for Americans to have only one close friend during their life-time, and consider other "friends" to be just social acquaintances. This attitude probably has something to do with American mobility and the fact that Americans do not like to be dependent on other people. They tend to "compartmentalize" friendships, having "friends at work" ,"friends on the softball team", "family friends", etc.

Because the United States is a highly active society, full of movement and change, people always seem to be on the go. In this highly charged atmosphere, Americans can sometimes seem brusque or impatient. They want to get to know you as quickly as possible and then move on to something else. Sometimes, early on, they will ask you questions that you may feel are very personal. No insult is intended; the questions usually grow out of their genuine interest or curiosity, and their impatience to get to the heart of the matter. And the same goes for you. If you do not understand certain American behavior or you want to know more about them, do not hesitate to ask them questions about themselves. Americans are usually eager to explain all about their country or anything "American" in which you may be interested. So much so in fact that you may become tired of listening. It doesn’t matter, because Americans tend to be uncomfortable with silence during a conversation. They would rather talk about the weather or the latest sports scores, for example, than deal with silence.

On the other hand, don’t expect Americans to be knowledgeable about international geography or world affairs, unless those subjects directly involve the United States. Because the United States is not surrounded by many other nations, some Americans tend to ignore the rest of the world.

It can be inferred from the passage that()

A. Americans want to participate in all kinds of activities

B. Americans’ character is affected by their social and geographical environment

C. Americans do not know how to deal with silence

D. curiosity is characteristic of Americans