以下关于电和磁的说法中正确的是（ ） A．磁场是由无数条磁感线组成的 B．改变通

下列分类等级中，生物的共同特征最多的是（　　）

A．界

B．属

C．门

D．种

如图所示，质量为2 kg的直角三棱柱A放在水平地面上，三棱柱的斜面是光滑的，且斜面倾角为37°.质量为1 kg的光滑球放在三棱柱和光滑竖直墙壁之间，A和B都处于静止状态，求地面对三棱柱的支持力和摩擦力各为多少?(g=10m/ssin37°cos37° 

阅读表达。

     While it is impossible to live completely free of stress (压力), it is possible to prevent stress as well as

reduce its effect when it can't be avoided. The US Department of Health and Human Services offers the

following suggestions for ways to deal with stress.

     Try physical activity

     When you are nervous, angry or upset, try releasing (释放) the pressure (压力) through exercise or

physical activity. Running, walking, playing tennis and working in your garden are just some of the activities

you might try.

     Take care of yourself

     You should make every effort to eat well and get enough rest. If you easily get angry and cannot sleep

well enough, or if you're not eating properly, it will be more likely that you will fall into stressful situations.

If stress repeatedly keeps you from sleeping, you should go to see a doctor.

     Make time for yourself

     Schedule time (确定时间) for both work and entertainment. Don't forget, play can be just as important

to your well-being (幸福) as work. You need a break from your daily routine (日常事务) to just relax and

have fun. Go window-shopping or work on a hobby. Allow yourself at least a half hour each day to do

something you enjoy.

     Make a list of things to do

     Stress can result from disorganization and a feeling that "there's so much to do,and not enough time".

Trying to take care of everything at once can be too much for you and as a result, you may not achieve

anything. Instead, make a list of everything you have to do, then _____, check off each task as it is

completed. Set out to do the most important tasks first.

1. What is the best title of the passage? (Please answer within 10 words.)

    _______________________________________________________________________________________

2. Which sentence in the passage can be replaced by the following one? You might feel stressed as a result

    of bad temper, poor quality of sleep or diet.

    _______________________________________________________________________________________

3. Please fill in the blank in the last paragraph with proper words or phrases to complete the sentence. (Please

    answer within 10 words.)

    _______________________________________________________________________________________

4. Which of the suggestions do you think is the best for you? Why? (Please answer within 30 words.)

    _______________________________________________________________________________________

5. Translate the underlined sentence in the last paragraph into Chinese.

    _______________________________________________________________________________________

JZ-7型制动机单独制动性能中，全制动位制动缸最高压力为（）Kpa。

A.280

B.300

C.360

D.450

焦油加工的主要任务是获得酚、萘、蒽等纯产品和（）等粗产品。