问题 填空题

近期,媒体报道的多起食品安全问题成为公众关注的焦点.菜贩为使大白菜等蔬菜保鲜喷洒甲醛(化学式为HCHO)溶液,酒店为延长海参存活期,用海水晶[含致癌物质亚硝 酸钠(NaNO2)]配制人造海水养海参,可口可乐(山西)饮料有限公司发布声明称,经检测该厂确认有9个批次的可口可乐产品中含极其微量的残留氯.试回答下列问题:

(1)在甲醛、亚硝酸钠、氯气三物质中,属于有机物的是_________

(2)甲醛中含碳、氢、氧元素的原子个数比为________(填最简整数比)

(3)在亚硝酸钠中,所含元素的质量分数最大的元素是__________

(4)氯气与水反应,生成次氯酸和盐酸,化学方程式为Cl2+H2O=HCl+HClO,在这个反应的两种生成物中,氯元素的化合价分别为_________

答案

(1)甲醛

(2)1:2:1

(3)氧元素

(4)-1,+1

单项选择题 共用题干题
阅读理解

阅读理解.

     There once was a group of tiny frogs(青蛙) who held a running competition. The goal

was to reach the top of a very high tower. A big crowd had gathered around the tower to

see the race and cheer on the contestants.(选手)

     The race began…

     Honestly, no one in the crowd really believed that the tiny frogs would reach the top of

the tower. You heard statements such as:

     "Oh, it's too difficult!"

     "They will NEVER make it to the top."

     "Not a chance that they will succeed. The tower is too high!"

     The tiny frogs began falling down, one by one…

     …except for those who in a fresh tempo(节奏) were climbing higher and higher…

     The crowd continued to shout, "It is too difficult! No one will make it!"

     More tiny frogs got tired and gave up… But one continued higher and higher and

higher …This one wouldn't give up!

    In the end, everyone else had given up climbing the tower, except for the one tiny frog

which, after a big effort(努力), was the only one who reached the top!

     Then all of the other tiny frogs naturally wanted to know how this tiny frog managed to

do it.

     A contestant asked the frog how he had found the strength to reach the goal. It turned

out that the winner was deaf.

1. The big crowd's statements showed that ________.

A. they tried to discourage the contestants

B. they thought the contestants would give up

C. they didn't believe that the contestants would succeed

D. they hoped that they could watch a wonderful game

2. As the crowd expected, the tiny frogs began to ________.

A. climb higher and higher

B. fall down one by one

C. make it to the top

D. beat each other

3. When asked how the succeeded, the winner ________.

A. didn't mention the secret

B. couldn't hear or answer at all

C. was too shy to answer

D. didn't care about it at all

4. The story mainly tells us that ________.

A. nothing is impossible if we put our heart into it

B. a deaf frog can run much faster than others

C. we shouldn't care about what others say if we want to succeed

D. we needn't spend too much time in looking for special skills.