关于视 * * 炎，说法错误的是（） A.猩红热可引起视 * * 炎 B.常伴视力及对比敏感度的

请依据下列信息回答有关问题：

Cl₂是一种黄绿色、具有刺激性气味、有毒的气体，其密度比空气的密度大。能与氢氧化钠溶液反应，生成氯化钠、次氯酸钠（NaClO）和水。Cl₂可用于漂白纸张、布匹以及消毒饮用水等。在实验室里常用下述反应制取氯气：

⑴写出氯气与氢氧化钠溶液反应的化学方程式：                              ；生成物中氯元素的化合价分别为               。

⑵实验室选择气体发生装置应考虑的因素有哪些？

⑶如上图，在实验室里制取氯气应选择的发生装置是         （填字母）；收集氯气选用D装置，请推测其中氢氧化钠溶液的作用是                                  。

⑷如上图，若选用B、E组合在实验室可制取                   气体，反应方程式为                                           。

⑸12.5g大理石与稀盐酸完全反应后,可生成二氧化碳气体4.4g,请计算大理石中杂质的质量分数.

It is difficult for parents of nearly every family to teach their children to be responsible for housework, but with one of the following suggestions, you really can get your children to help at home.

If you give your children the impression that they_____________________, then they will regard themselves as unfit or unable persons. Unless children believe they can succeed, they will never become totally independent （独立）.     

My daughter Carla’s fifth-grade teacher made every child in her class feel special. When students received less than a perfect test score, she would point out what they had mastered and declared firmly they could learn what they had missed.

You can use the same technique when you evaluate （评价）your child’s work at home. Don’t always scold and give lots of praise instead. Talk about what he has done right, not about what he hasn’t done. If your child completes a difficult task, reward him with a Sunday trip or a ball game with Dad.

Learning is a process （过程）of trying and failing and trying and succeeding. If you teach your children not to fear a mistake of failure, they will learn faster and achieve success at last.

1.What’s the best title of the passage?    

2.Which sentence in the passage is the closest in meaning to the following one?

The process of learning is full of trying and failing ,and after trying again and again ,one will succeed.

3.Please fill in the blank in the passage with proper words or phrases to complete the sentence.(within ten words)

4.What do you think parents should do to educate their children well according to the passage?(within 30 words)     

5.Translate the underlined sentence into Chinese.

世界上第一台电子数字计算机ENIAC诞生于( )年。

A．1946

B．1956

C．1942

D．1940

当人们无偿地享有了别的经济体带来的额外收益时，经济学中称之为（）

A.公 * * 品

B.外部经济

C.交易成本

D.外部不经济

固定桥桥体龈面与牙槽嵴黏膜的接触有多种形式，目前应用最多的桥体形式是

A．全自洁型
B．单侧接触式
C．船底式
D．“T”形式
E．鞍基式