试述可编程序控制器的基本结构及各部分的作用。

第二节：（共5小题；每小题2分，满分10分）

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

71  One of the best things you can possibly do is to start your own club .It 's great fun especially if you're the sort of person who feels there 's never anything to do during the school holidays.

The first thing you need to come up with is an idea for your club.  72  Pets, clothes, pop music or dancing groups ,sports ,making things? The list is endless.

Next you need some friends to be in your club with you.  73  All you need is three or four other people who are interested in the same things as you.

74  You should all sit down somewhere together with lots of pieces of paper and write down every name you can think up. That 'll keep you busy for ages.

At your first meeting you should make up a rule book .And the very first rule should be no grown-ups or little /big brothers /sisters ! The best clubs are always secret!

Now you have just about everything you need, except membership cards. These are very important and again you can spend a lot of time making them.  75   Why not leave some space for a photo of yourself? That will make the membership card really look like it.

So there you are, get clubbing ! Once you get started you'll think of loads of more interesting things to do!

A．That's easy

B．Enjoy your own club!

C．Invite a designer to join you.

D．What are you interested in? E. Summer vacation is just around the corner.

F. Then you need to pick a name for your club.

G. Use bright thick pens to make a special design.

ABC会计师事务所接受委托，对甲公司20×9年度财务报表进行审计。A注册会计师为甲公司年报审计的项目负责人，根据审计业务的要求，组建了甲公司审计项目组。假定存在下列情形：

(1) A注册会计师与甲公司副总经理同为油画爱好者，经其介绍，A注册会计师从其他企业筹得款项，成功举办个人油画展；

(2) 审计项目组成员B与甲公司后勤处处长是战友，在年底审计的时候将甲公司职工年终福利一台进口彩电赠送给了B；

(3) A注册会计师的岳父于20x8年购买甲公司发行的公司债券，面值2000元，即将到期；

(4) ABC会计师事务所合伙人C不属于项目组成员，其妻子继承父亲遗产，其中包括甲公司内部职工股20000股；

(5) 审计项目组成员D与甲公司财务总监王总从小学到大学一直是同班同学；

(6) ABC会计师事务所原人事部经理E于20×5年10月离开事务所，担任甲公司人事总监。

要求：

针对（5）事项，指出是否对审计项目组的独立性构成不利影响，并简要说明理由。

碳质还原剂的主要性能有电阻率，化学活性和石墨化性能。

第四次全国人民防空会议确定的人民防空工作方针是（）

A.着眼全局，统筹规划

B.同步建设，协调发展

C.长期准备，重点建设，平战结合

下列哪些因素可降低细胞膜的流动性（）

A.脂肪酸链的长度増加

B.脂肪酸链的不饱和程度増加

C.卵磷脂与鞘磷脂比例增加

D.相变温度以上胆固醇含量増加

E.相变温度以下胆固醇含量増加