菱形的两邻角之比为1：2，较短的对角线为6cm，则菱形的周长为______cm，

血小板中含量最丰富的蛋白质是（）

A.糖蛋白

B.肌动蛋白

C.收缩蛋白

D.肌球蛋白

E.微球蛋白

下表反映了19世纪末20世纪初主要资本主义国家煤钢增长情况，对表中信息解读正确的是   

A．美国已成为资本主义世界头号强国   

B．英国在世界贸易中占据绝对优势地位   

C．英国霸权地位被美德取代   

D．英国“世界工厂”地位受到严重挑战

阅读理解

     We all know how important human life is-it's priceless. It doesn't matter where you are from or what

the color of your skins is-all people are human beings. Firstly, we can tell you that the lives of your

relatives could depend on your ability to give first aid. If you think highly of human's life, this website is

for you! Here you can find information about first aid.

     The very first thing that you should do when you see an accident is to evaluate the situation and

prevent further dangerous incidents. First of all, you have to recognize what has happened and what the

dangers to rescuers and victims are. Think about how to take care of the victims.

     Helping usually takes place in very difficult conditions and injuries can be very bad. Therefore, you

cannot be too afraid of making mistakes to help. Sometimes you have to face the fact that regardless of

your actions and your efforts the victim's condition might not improve-he or she could even die. In some

cases even professional medical aid may not succeed. If you have done everything you think you should

do, you shouldn't feel guilty.

     Do not expose yourself to danger. Giving first aid can be dangerous. While trying to help a victim, do

not forget about your own safety. If something happens to you, you won't be able to help anyone.

     Call for help after you find out the condition of a victim. But remember if a victim faints due to

breathing failure caused by drowning, choking or poisoning, you should first take actions that help to

bring back the heart beat and breathing. While calling, talk shortly but clearly. Always provide the

following information: the location of the accident, the kind of accident, the number of the injured and

your full name and phone number and so on.

1. The passage is probably taken from _________.

A. a newspaper    

B. the Internet    

C. a textbook    

D. a guide book

2. The underlined word " evaluate" in Paragraph 2 is closest in meaning to _______. 

A. leave    

B. protect    

C. avoid    

D. judge

3. What's the main idea of Paragraph 3?

A. You should learn some professional knowledge about first aid.

B. You shouldn't feel guilty if you don't know about first aid.

C. Try your best to give first aid and don't be afraid of making mistakes

D. Don't make mistakes when you are giving first aid.

4. The author thinks that helping a victim can be ____________.

A. risky    

B. shocking    

C. exciting    

D. boring

5. It can be inferred from the passage that __________.

A. young people must learn how to give first aid

B. you should forget about your own safety while giving first aid.

C. when you see an accident you should do nothing but call the police.

D. when calling for help you should give all relevant details.

合金元素的总含量小于（）的钢，称低合金钢。

A.4％

B.5％

C.6％

D.7％

路线中线的平面线形是由直线和（）组成的

A.折线

B.曲线