一均匀加宽固体激光器，当中心频率处的小信号增益系数G0=2Gth，则振荡线宽（①）增

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       Germs(细菌 ) are everywhere. You can't see them, but they are on your desk,on your computer,

and even in the air !

       Like people,germs move around the world. They fly with us on planes. When food, clothes, and

other things travel around the world,germs travel,too. Some germs are safe,but some are dangerous.

Germs cause illnesses like colds and the flu.

Warmer Weather Brings Germs

       The world's weather is changing. Cooler countries are getting warmer, so insects from hot countries

can move there. Some of these insects,like mosquitoes,carry dangerous germs. These germs cause

headaches, fever, and can even kill people.

Under Your Skin

       Your skin protects you from germs. It stops some germs,but not all. They can enter your body when

you eat,or when you have a cut. Germs are on your hands, too. They enter your body when you touch

your eyes, nose , or  mouth.

Fighting Germs

       Your immune system(兔疫系统) protects you, too. When germs get inside your body,your immune

system finds and kills them. Special cells (细胞) move around your body and fight germs. They help you

stay healthy. Other cells make antibodies. Antibodies help your body

find and stop germs.

       What can you do to fight germs? You should wash your hands with soap and water. Soap kills many germs, and water washes them away.

1. According to the text,insects                  .

A. kill germs      

B. carry germs      

C. protect germs    

D.love germs

2. The underlined word "there" refers to                    .

A. cooler countries  

B. hot countries    

C. everywhere      

D. the world

3. Which of the following is RIGHT according to the text ?

A. All germs are dangerous.      

B. There are more germs in cold places.

C. Soap can kill all germs.      

D. Germs can get into your body.

4. What do antibodies do?

A. They kill germs and wash them away.    

B. They find and develop germs.

C. They help protect us from germs.        

D. They carry dangerous germs.

5. Which can be the best title for this text?

A. Germs Are Everywhere                

B. Weather Is Changing

C. Skin Stops Germs                    

D. Germs Are Developed

李自鸣为某研究院软件开发商，他利用业余时间为东方电脑公司开发软件并提供一年的维修服务。按约定，他可以得到劳务报酬36000元。他可以要求对方事先一次性支付该笔劳务报酬，也可以要求对方按软件维护期分12个月支付，每月支付3000元。那么在不考虑时间价值的情况下，理财师应该给他的建议是( )。

A．选择一次性支付，因为可以少纳税1360元

B．选择一次性支付，因为可以少纳税3520元

C．选择分次支付，因为可以少纳税1360元

D．选择分次支付，因为可以少纳税3520元

我国的北方，冬天对自来水管的保护十分重要，否则会把水管冻裂，影响人民的生活，小红学习了密度知识后，对上述现象进行了如下计算和分析，首先她查表知道，冰的密度为0.9×10³kg/m³， 水的密度为1.0×10³kg/m³，体积为1dm³的水，结成冰后

（1）计算冰的质量为多少?

（2）计算冰的体积为多少？

（3）解释水管冻裂的原因？

尼日尔是一个多民族国家，最大的部族是（）。

A.哲尔马-桑海族

B.颇尔族

C.豪萨族

D.图阿雷格族

干粉灭火器内装药粉的容量是（）kg。

A、4～6

B、4～8

C、5～8

D、5～10