机车升弓电流对信号设备有什么影响？有什么防护措施？

阅读下面短文，简要回答所给问题。

     The first Earth Day was in 1970. People were beginning to worry about what we were doing to our

environment. So they set up Earth Day to tell everyone about their worries.

     In 2007 organizers m over 150 countries planned over 4,000 big events. But Earth Day is not just about

marches (游行) and big events. In the week around Earth Day (22 April) there were many thousands of

smaller, local events. These events dealt with environmental problems in the neighborhood.

     The World Wide Fund for Nature made a list of 5 things that each person could do to save the environment. 

     * Don't leave the tap running.

     * Turn off lights when you leave a room.

     * Turn off your computer every night.

     * Wash your clothes, and yourself, in warm or cold water, not hot water.

     * Dishwashers use as little water as possible. If we all do at least 2 0f these all the time, we can make a big

difference.

1. What is the purpose for people to set up Earth Day?

    ________________________________________________________________________________

2. When is Earth Day? 

    ________________________________________________________________________________

3. What should people do when the water keeps running from a tap? 

    ________________________________________________________________________________

4. Does the word "dishwashers" mean "machines for washing dishes"?

    ________________________________________________________________________________

5. Besides the five, what else can you do to save our environment? (One example is OK.) 

    ________________________________________________________________________________

某一施工现场需要填土，其坑的体积为20×20×5=2000m³，土方的来源是从附近土丘开挖。经勘察，该土的相对密度d_s=2.70，含水量ω=15%，孔隙比e=0.60。要求填土的质量是含水量ω=17%，干重度γ_d=17.6kN/m³。

①该饱和黏性土的孔隙比、干密度和饱和密度依次为（）。

A．0.912 1.5g/cm³ 1.85g/cm³

B．0.912 1.6g/cm³ 1.85g/cm³

C．0.819 1.6g/cm³ 1.95g/cm³

D．0.819 1.5g/cm³ 1.95g/cm³

在继电器控制的开关电路中，继电器线圈两端必须并联反向二极管。

服务投标文件的内容不包括( )。

A．投标保证金
B．联合体协议书
C．投标函及投标函附录
D．投标一览表

关于锂聚合物电池参数描述正确的是（）。

A.C数是指电池电芯的串联数

B.S数是指电池电芯的并联数

C.P数是指电池电芯的放电倍率

D.容量的单位是Mah或者Ah