问题 选择题

下列反应的离子方程式书写正确的是

①硫酸铜溶液与氢氧化钡溶液反应:Ba2=BaSO4

②将金属钠加入水中:2Na+2H2O=2Na+2OH+H2

③石灰石溶于稀醋酸:CaCO3+2CH3COOH=2CH3COO+Ca2+CO2↑+H2O

④氯气与水反应:Cl2+H2O=H+Cl+HClO

⑤小苏打溶液中加入少量石灰水:Ca2+2OH+2=CaCO3↓++2H2O

⑥次氯酸钙溶液中通入过量CO2:Ca2+2ClO+CO2+H2O=CaCO3↓+2HClO

⑦钠与硫酸铜溶液反应:Cu2+2Na=Cu+2Na

⑧纯碱溶液中滴加少量盐酸:+H=

A.①②⑤

B.②③④⑤⑧

C.④⑤⑥⑦

D.②③⑧

答案

答案:B

①漏写Cu(OH)2;⑥CO2过量,应生成;⑦钠投入水溶液中,先与水反应生成NaOH,再与Cu2生成Cu(OH)2

填空题
阅读理解

阅读理解。

      Most people say" yes" much more readily than" no".

     A friend is moving house this weekend and would like some

help,and you agree. But, what you really wanted was relaxing at

home for a couple of quiet days,or a roommate spends the whole

weekend playing video games and wants to borrow your homework

for"reference". But,you've just finished it after working hard for a

whole day.

     Many people say" yes" to this kind of requests. They tend not

to consider their own interests and feelings,and are often angry with

themselves afterwards. Saying" no" requires courage and considerable

practice. " Everyone wants to be liked. " says Gabriele Steinki,a

German psychologist. "Saying'no'risks losing the affection of the

person asking for the favor. Or even a job. "The result is that many

people say"yes"just for keeping the peace. But experts say this is

regrettable. Anyone should have the right to say" no". In fact, rejecting

a request can even help to stabilize a relationship because it

expresses real affection. But,for peop'le accustomed to agreeing every

request,it's very distressing to say" no".

     Most people believe that if they say" no" ,they'll lose the affection

of the person. But the affection is important to them. This way

of thinking can be replaced by this:"If he only likes me because I

always do what suits him,then the price of this affection is too high

in the long term. "

    When people say " no", Steinki advises giving the reasons

calmly until the person gets the message.

1. What does the second paragraph tell us?  

A. In fact people are usually selfish.

B. Sometimes people say " yes" when they really want to say no .

C. It's not suitable to ask others to help at weekends.

D. It's disgusting to borrow homework for reference.

2. Many people don't say" no" though they really want to because    

A. they dare not offend the asker

B. they are afraid of breaking the good relationship with the asker

C. they don't care about their own feeling

D. they are good-tempered

3. The underlined word" distressing" can be replaced by "____ ".   

A. comfortable                      

B. funny

C. unnecessary                    

D. uncomfortable

4. The best title for the passage would be _____.  

A. You Need Courage to Say "No"

B. Saying" No"Is More Important Than Saying" Yes"

C. Saying " No" Would Bring Benefits

D. The Art of Saying " No"