在25℃下，将a mol·L-1的氨水与0.01mol·L-1的盐酸等体积混合后

习 * * * * 指出，青年在哪里，团组织就建在哪里；青年有什么需求，团组织就要开展有针对性的工作，努力使团组织成为（）和（）青年的坚强堡垒。

A.联系/服务

B.管理/服务

C.组织/服务

阅读理解。

     Imagine, one day, getting out of bed in Beijing and being at your office in Shanghai in only a couple of

hours, and then, after a full day of work, going back home to Beijing and having dinner there.

     Sounds unusual, doesn't it? But it's not that unrealistic, with the development of China's high-speed railway

system. And that's not all. China has an even greater high-speed railway plan-to connect the country with

Southeast Asia, and eventually Eastern Europe.

     China is negotiating to extend its own high-speed railway network to up to 17 countries in 1 0 to 15 years,

eventually reaching London and Singapore.

     China has proposed three such projects. The first would possibly connect Kunming with Singapore via

Vietnam and Malaysia. Another could start in Urumqi and go through Kazakhstan and Uzbekistan, and possibly

to Germany. The third would start in the northeast and go north through Russia and then into Western Europe.

     If China's plan for the high-speed railway goes forward, people could zip over from London to Beijing in

under two days.

     The new system would still follow China's high-speed railway standard. And the trains would be able to go

346 kilometers an hour, almost as fast as some airplanes.

     China's bullet train (高速客车), the one connecting Wuhan to Guangzhou, already has the World's fastest

average speed. It covers 1,069 kilometers in about three hours.

     Of course, there are some technical challenges to overcome. There are so many issues that need to be

settled,such as safety, rail gauge (轨距), maintenance of railway tracks. So, it's important to pay attention to

every detail.

     But the key issue is really money. China is already spending hundreds of billions of yuan on domestic

railway expansion.

     China prefers that the other countries pay in natural resources rather than with capital investment. Resources

from those countries could stream into China to sustain development.

     It'll be a win-win project. For other countries, the railway network will definitely create more opportunities

for business, tourism and so on, not to mention the better communication among those counties.

     For China, such a project would not only connect it with the rest of Asia and bring some much-needed

resources, but would also help develop China's far west. We foresee that in the coming decades, millions of

people will migrate to the western regions,where the land is empty and resources unused. With high-speed

trains, people will set up factories and business centers in the west once and for all. And they'll trade with

Central Asian and Eastern European countries.

1. China's new high-speed railway plan will be a win-win project because _____. [ ]

A. China will get much-needed resources and develop its western regions

B. China and the countries involved will benefit from the project in various ways

C. China will develop its railway system and communication with other countries

D. the foreign countries involved will develop their railway transportation,business and tourism

2. According to the passage,the greatest challenge to the new high-speed railway plan is _____. [ ]

A. technical issues

B. safety of the system

C. financial problems

D. maintenance of railway tracks

3. Which of the following words best describes the author's attitude towards China's high-speed railway plan?

A. Critical.

B. Reserved.

C. Doubtful

D. Positive.

4. Which of the following might be the best title for the passage?[ ]

A. New Railway Standards

B. Big Railway Dreams

C. High-speed Bullet Trains

D. International Railway Network

-1/2²，-1/3³，-1/4⁴，________ ( )

A．1/5²

B．-1/5

C．-1/5⁵

D．－1/5⁴

1923年12月21日，孙中山先生在怀士堂演讲时对学生的教导是什么？

机组停机或扩大性大修时，应检查哪些结构？