某厂商生产一批产品，生产第5个单位产品的总成本是4.1元，生产第6个单位产品总成本是

在2003年底重庆开县的天然气井喷事故中，剧毒气体硫化氢（H₂S）是造成重大人员伤亡的罪魁祸首．事故发生后，专家先是点燃出事气井，因为硫化氢在空气中点燃完全燃烧时生成二氧化硫（毒性相对较小）和水．试回答：

（1）硫化氢中硫元素的化合价为______价．

（2）写出硫化氢在空气中完全燃烧的化学方程式：______，该反应中的还原剂是______．

A、H₂S          B、SO₂           C、O₂            D、H₂O

（3）已知H₂S水溶液的pH小于7，则向其中滴加1～2滴紫色石蕊试液，溶液呈______色．

A、B、C都是金属，A和C分别放入同浓度的稀硫酸中，A的反应速率比C快，A与B和硫酸铜溶液组成原电池时，A的质量增加。A、B、C三种金属的活动性顺序为[ ]

A．A>B>C

B．A>C>B

C．B>A>C

D．C>A>B

场景(十五) 2008年8月3日，甲建筑公司与乙采砂场签订了一个购买砂子的合同，合同中的约定砂于的细度模数为2.4。但是在交货的时候，经试验确认所运来的砂子的细度模数是 2.2。于是甲建筑公司要求采砂场承担违约责任。2008年8月4日，经过协商，达成了一致意见，甲建筑公司同意接收这批砂子，但只需支付98%的价款就可以了。2008年8月20日，甲建筑公司反悔，要求按照原合同履行并要求乙采砂场承担违约责任。
根据场景(十五)，回答下列问题：

下列表述中，正确的有( )。

A．作为原合同的补充，和解协议没有法律效力

B．作为原合同的补充，和解协议的效力高于原合同

C．甲建筑公司提出按照原合同履行的要求不应予以支持

D．如果甲公司不按协议执行，则乙采砂场可以申请强制执行

E．如果甲公司不按协议执行，则乙采砂场可以追究其违约责任

监管证件代码“A”代表出境货物通关单。 （）

信息匹配

阅读下列应用文及相关信息, 并按照要求匹配信息.

首先请阅读下列几本儿童书籍的封面及提示性文字:

A.  I Will Hold You Til You Sleep

B.  Two Finger Puppet Magnet Books

C.  I SPY TREASURE HUNT                 

D.  Disney's Little Einsteins

E.  The Wonderful Wizard of Oz                

F.  Learn About Math With Bert & Ernie

以下是5本儿童书籍的介绍.请将它们与之对应的书籍匹配起来.

1.  Based on the new hit animated show airing on the Disney Channel, this new series takes preschoolers

along on the thrilling adventures of Leo, June, Quincy, and Annie, whose missions are illustrated with

beautiful, fullcolor photos.EmmyAward winner Susan Ring specializes in writing for children, and has

written for all types of media.Her books for Disney Publishing Worldwide include Winnie the Pooh

Encyclopedias on Animals and Nature; boxed sets of Pixar's Fun with Phonics, featuring Nemo and

Toy Story characters; and the Baby Einstein books.

2.  Here is the rare book that not only expresses a parent's love for their child, but offers a hope for what

that love will become.It begins with a wish at bedtime, as parents hold their children tight and hope their

love will cradle them, safe and sound.It continues through the day their children have grown up, proud

and strong, and can pass that love on to someone else.This is a book that goes beyond a parent's "I love

you" to the generous wish that our children will make the world a better place.

3.  This bestselling book features riddles that send readers searching through 13 photographs with a fun

house theme.Children will love to purse the mystery of the pirate's hidden treasure, narrowing their

search with every delightfully cluttered page.Looking for an additional challenge? Try the extracredit

riddles.

4.  Pooh, Piglet, and the gang from the HundredAcre Wood are here to guide you through some amazing

activities.Just slip one of the pointing puppets onto your finger, and see if you can solve the puzzles inside.

Your puppet will be drawn to the solutions, and your heart will be hooked by the colorful crew! This

book includes 2 magnetic finger puppets.

5.  This exciting new workbook from Sesame Workshop and Learning Horizons is designed so your

child can have fun learning right along with Big Bird and the other friends from Sesame Street! In this

workbook, your child will learn to recognize numbers, count and match sets of like items.Your child will

even begin to add and subtract! A special "think icon" feature calls attention to activities that are

challenging and more advanced.A special Explore More Feature provides several easytodo home

activities to extend learning in practical and fun ways.