Chinaisan ___________ country.[ ] A.west

分析步行中下肢肌群的肌电图特征时，需要在足底安装脚踏开关，其目的在于（）。

A.采集肌电信号

B.区分步行周期的站立相和摆动相

C.分析步态是否存在异常

D.计算步行周期所走距离

E.以上全对

一质量为1kg的物块在水平地面上向右滑行，物块与地面间的动摩擦因数为μ＝0.2，从t＝0时刻开始受到一水平向左的恒定外力F＝1N的作用，则反映物块所受摩擦力随时间变化的图象是(取向右为正方向)(　　)

下列环境问题属于全球性环境问题的是      

A．大气污染

B．土壤污染

C．城市垃圾

D．水土流失

In summer, millions of people will head for the beach. And while the ocean can be a great place to swim and play, it may also be useful in another way. Some scientists think that waves could help make electricity.

“Have you ever been on a surfboard or boat and felt yourself being lifted up by a wave? Or have you jumped in the water and felt the energy as waves crashed over you?” asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh in Scotland．“There is certainly a lot of energy in waves．”

Scientists are working on using that energy to make electricity．

Most waves are created when winds blow across the ocean．“The winds start out by making little ripples (波纹) in the water, but if they keep on blowing , those ripples get bigger and bigger and turn into waves, ”Taylor said．“Waves are one of nature’s ways of picking up energy and then sending it off on a journey．”

When waves come towards the shore, people can set up dams or other barricades to block the water and send it through a large wheel called a turbine (涡轮) ．The turbine can then power an electrical generator (发电机) ．

The United States and a few other countries have started doing research on wave energy , and it is already being used in Scotland．

The resource is huge．We will never run out of wave power, besides, wave energy does not create the same pollution as other energy sources, such as oil and coal．

Oceans cover three quarters of the earth’s surface．That would make wave power seem perfect for creating energy around the world．There are some drawbacks, however．

Jamie Taylor said that wave power still cost too much money．He said that its effects on animals in the sea were still unknown．Plus, wave power would get in the way of fishing and boat traffic．

With more research, however, “many of these problems might be overcome,” Taylor said．“Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is growing quickly throughout the world．Finding more energy sources is very important, for traditional sources of energy like oil and gas may run out some day．”

In the future, when you turn on a light switch, an ocean wave could be providing the electricity!

68．Which of the following is NOT true?

A．Wave power costs too much money．

B．Wave energy creates the same amount of pollution as other energy sources．

C．Wave power affects fishing and boat traffic．

D．Wave power may affect marine animals．

69．We can infer from the passage that ______．

A．finding more new energy sources is not necessary because of wave energy

B．wave energy is a resource that will never run out and is used all over the world

C．wave power is perfect for creating energy around the world

D．wave power doesn’t create any pollution

70．The underlined word “drawbacks” probably means ______．

A．regrets      B．adventures       C．disadvantages          D．difficulties

71．What can be the best title for the passage? 

A．How to Get Electricity by Waves．       B．The Advantages of Wave Energy.

C．Can Waves Make Electricity?  D．The Disadvantages of Wave Energy．

下列不属于资产负债表揭示的财务信息是( )。

A．企业拥有并可利用的经济资源，包括资产总额、结构和分布情况
B．揭示了企业负债的水平与构成等
C．表明了企业所有者权益的多少、构成状况等
D．一定时期企业的盈亏状况