已知H2(g)、C2H4(g)和C2H5OH(l)的燃烧热分别是285.8kJ•

题型:选择题

问题:

已知H2(g)、C2H4(g)和C2H5OH(l)的燃烧热分别是285.8kJ•mol-1、1411.0kJ•mol-1和1366.8kJ•mol-1,则由C2H4(g)和H2O(l)反应生成C2H5OH(l)的△H为(  )

A.-44.2 kJ•mol-1

B.+44.2 kJ•mol-1

C.-330 kJ•mol-1

D.+330 kJ•mol-1

考点:盖斯定律
题型:选择题

阅读理解。

     Helen Keller was a very clever and beautiful girl. At the age of six months she could already say a few

words. But before she was two years old, she was badly ill. She could not see or hear, and soon, she could

not even talk, then Helen had to fight for what she wanted.

     When she was six, her parents invited a teacher for her. With the help of the teacher, she began to see

and hear the world around her through her hands. She learned to read the books for the blind (盲人). The

teacher took Helen for long walks, and told her about all the beautiful sights. Helen touched flowers, climbed

trees, and smelled a storm before it came. She also learned how to swim and ride a horse.

     After she grew up, she became a famous writer in America. Her first and most famous book is The Story

of My life. Her story has brought new hope to many blind and deaf people . It gave light to those in Darkness

and encouraged them to live and work.

1. When could Helen Keller already say a few words? [ ]

A. At the age of two.

B. At the age of a year and a half.

C. At the age of six months.

D. When she was six years old.

2. Why couldn't Helen see or hear later? [ ]

A. Helen was badly ill.

B. She had a traffic accident.

C. Helen was very tired.

D. She became very lazy.

3. How could Helen begin to see and hear the world around her? [ ]

A. With the help of her father.

B. She could see and hear the world around her through her feet.

C. With the help of her parents.

D. With the help of her teacher she could begin to see and hear through her hands.

4. After Helen grew up she became a famous _____. [ ]

A. doctor

B. scientist

C. singer

D. writer

5. What gave light to those in darkness and encouraged them to live and work? [ ]

A. The teacher's help.

B. The parents' help.

C. Helen's story.

D. Helen's songs.

题型:选择题

阅读理解,回答问题。

     Mrs. Green is going to give Mary a birthday party. Mary is her daughter. She will be ten years old.

A lot of her friends are coming to the party. Twenty of them are girls.

     Mrs.Green is getting ready for the party. Mrs.White is helping her.

     "That's a big nice cake," says Mrs.White to Mrs.Green.

     "Thank you very much."

     Mrs.Green is going shopping now.She is going to buy fruit for the party.Mrs.Green buys a lot of

pears, apples, oranges and bananas. Then she goes home.

     It's five o'clock in the afternoon. Everything is ready. Now the first girl is arriving. The party is going

to begin in thirty minutes.

1. Who is Mrs.Green going to give a birthday party to?

    _______________________________.

2. How old is Mary now?

   _______________________________.

3. What does Mrs.Green buy fruit for?

   _______________________________.

4. When is the party going to begin?

   _______________________________.

5. How many girls are there at the party?

   _______________________________.

题型:选择题

平行投影是由______光线形成的.

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采用盐酸萘乙二胺分光光度法测定空气中甲基对硫磷时,配制甲基对硫磷标准储备液的方法是:称取0.0500g甲基对硫磷晶体,溶解于蒸馏水,定量移入25m1容量瓶中,并用蒸馏水定容至标线。

题型:选择题

政府用繁荣年份的财政盈余来补偿萧条年份的财政赤字,以缓解经济的周期性波动,这种财政政策是指( )。

A.汲水政策

B.自动稳定的财政政策

C.补偿性财政政策

D.中性财政政策

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