题目内容

【题目】回答下列问题:

(1)从鸡蛋白的溶液中提取蛋白质的方法有________和________。

(2)鸡蛋腐烂时,常闻到有刺激性气味的气体,该气体主要是________,说明蛋白质中含有________元素。

(3)误食重金属盐会中毒,这是因为_________________。

(4)浓硝酸溅到皮肤上,使皮肤呈现________色,这是由于浓硝酸和蛋白质发生了________反应的缘故。

(5)鉴定一种织物的成分是真丝还是人造丝,可各取一小块进行________,这是因为______________________。

【答案】(1)盐析 渗析

(2)H2S

(3)重金属盐会使蛋白质变性

(4)黄 颜色

(5)灼烧 真丝是蛋白质,灼烧时有烧焦羽毛的气味

【解析】(1)提取蛋白质的方法可以从两方面考虑,一是让蛋白质沉淀出来,一是让其他物质分离出去;(2)鸡蛋腐烂时,蛋白质分解放出的硫化氢气体具有刺激性气味;(3)重金属离子会使蛋白质变性;(4)蛋白质可与浓硝酸等许多试剂发生特殊的颜色反应;(5)人造丝是合成纤维,真丝是蛋白质,两者灼烧时的气味不同。

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【题目】A

Buildings crashed to the ground in seconds. Thousands of people lost their lives in a flash. Since they were told an earthquake would hit Tokyo around September 16, Japanese people havent been able to get these thoughts out of their minds.

They heard the news from Yoshio Kushida, a researcher who used radio waves to predict that an earthquake would strike with a magnitude(量级) of at least seven.It would be terrible not to warn people of a possible disaster in case a quake actually occurs, he said.

His warning had a big effect. Frightened Tokyo people have been stocking up on water, food and candles in preparation for the terrible day.

But Kushida hasnt had much support from the experts. At present, predicting earthquakes is thought to be impossible. No one can tell exactly where or when the next major earthquake will occur. An earthquake begins tens of miles below the earths surface: its too faraway to see.

Ancient Chinese and Italian scientists forecast earthquakes by special earthquake clouds. They found that a week before an earthquake, there were often strange clouds shaped like snakes, waves or feathers in the sky. They thought the clouds might come from a gas produced underground by an earthquake.

People also used to watch animals to see if earthquakes were coming. When they saw birds fly away suddenly, dogs barking violently or fish jumping out of the water, they told people to leave the area. Some scientists believed animals had a sharper sense of changes taking place underground.

But the ancient methods were not reliable enough. Nowadays, scientists use special instruments to predict earthquakes more precisely(精确地).

Satellite systems are very useful: they record small changes in the earths magnetic fields(磁场) which help show where and when an earthquake may strike.

【1】Since they were told an earthquake would hit Tokyo, Japanese people__________.

A. have had no mind to do their work

B. have always thought great damage it may cause

C. have almost forgotten about it

D. have bought all the foods in the markets

【2】 Which of the following is TRUE?

A. Tokyo people were surprised at the warning.

B. Great disasters would happen if people are not warned of before an earthquake.

C. Predicting earthquakes is completely impossible at present science level.

D. According to ancient people,before an earthquake we can see strange clouds anywhere.

【3】Which is the best way to predict earthquakes nowadays?

A. Watch animals. B. By specialearthquake clouds.

C. Use satellite systems. D. Theres no way.

【4】Which can be the best title for the passage?

A. Earthquake prediction. B. Magnetic fields.

C. Earthquakes. D. An earthquake in Japan.

【题目】B

Montgomery County Special Olympics held its eighth yearly show of unified (联合的)basketball at Blessed Sacrament School. The gym was filled with cheerleaders (啦啦队队员), parents and friends. The walls were covered with posters made by thirdandfourthgraders at the school. And all the elementary, middle and high school unified teams were playing hard and having fun. Every basket, no matter which team scores, is cheered and celebrated.

Special Olympics support more than 20 unified games. What are unified games? They are programs designed for players with special needs. In the games, they play with kids who are volunteers, called unified partners. The special athletes are unable to play normally like other healthy kids, and some of them are wheelchair (轮椅) users. In basketball, the unified partners rebound (抢得篮板球), pass and sometimes push a special athletes wheelchair. As Brian Ross, a seventhgrader at St. Albans School in Washington, says, You just try to help and get everyone to take part.

Some special athletes have come a long way to be where they are. Caleb Head is a 15yearold special athlete. When he started, Caleb would only stand at the door and watch. Then Caleb began to practice his shooting but still would not play in the games. Now Caleb runs up and down looking for his shot.

The special athletes are not the only ones who benefit (受益) from unified sports; the unified partners do, too. Marla Grusin, whose son Tyler is a special athlete, says every kid should come to a Special Olympics game. If they do, they will learn to share the ball and that the game is not all about me.

Not a bad lesson for any athlete.

【1】The first paragraph is about____________.

A. the meaning of unified games

B. Special Olympics development

C. the benefits of playing basketball

D. an exciting unified basketball game

【2】Special Olympics are especially held for students who____________.

A. are disabled

B. love cheerleading

C. know little about ball games

D. want to become a star player

【3】 According to the text, Brian Ross is most probably____________.

A. a cheerleader B. a special athlete

C. a unified partner D. a basketball teacher

【4】According to Grusin, taking part in Special Olympics games can help children____________.

A. learn basic basketball skills

B. become more selfless

C. improve their health

D. get better grades

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