发电厂、变电所中，验算硬导体短路动稳定时，对应于导体材料的破坏应力，安全系数取下列哪

一个半径为0.5m的飞轮做匀速圆周运动时，每分钟300转，则其边缘上一质量为0.1千克的金属块的线速度为______m/s，向心加速度大小为______m/s²，所受合力大小为______N．

人类进入近代以来，先后开展了三次工业革命、科技革命，极大地推动了人类历史的进步。结合所学知识，回答有关问题。（10分）

（1）工业革命开始于哪个部门？工业革命后人类历史进入了什么时代？（2分）

（2）第二次科技革命将人类带入什么时代？谁被誉为“发明大王”？（2分）

（3）第三次科技革命以什么为核心标志？试举一例我国近几年来在航天技术方面取得的伟大成就。（4分）

（4）三次科技革命都促进了人类社会的进步。由此说明了什么道理？（2分）

用盈余公积弥补亏损时，正确的会计处理为借记“盈余公积”科目，贷记( )。

A．本年利润
B．利润分配一未分配利润
C．利润分配一其他转入
D．利润分配一提取盈余公积

2005年“3.15”消费者日的主题是“健康、 * * ”。据此，某班同学设计了主题班会的四个题目，你认为不符和“3.15”主题精神的题目是（）。

A、“生命健康权——以人为本的体现”

B、“知悉权、自主选择权、求偿权——让我们运用权利”

C、“让我们充分运用公民最基本的权利”

D、“健康——和谐—— * * ——和谐”

World Water Shortage

A new study warns that about thirty percent of the world’s people may not have enough water by the year 2025.
A private American organization called (1) Action International did the new study. It says (2) than three-hundred-thirty-five-million people (3) enough water now. The people live in twenty-eight (4) . Most of the countries are in Africa or the (5) East.
P-A-I researcher Robert Engelman says (6) the year 2025, about three-thousand-million people (7) lack water. At least 18 more countries are (8) to have severe water problems. The demand (9) water keeps increasing. Yet the amount of water on Earth (10) the same.
Mr. Engelman says the population in countries that lack water is (11) faster than in other parts of the world. He says (12) growth in these countries will continue to (13) .
The report says lack of water in the future may (14) in several problems. It may increase health (15) . Lack of water often means drinking (16) not safe. Mr. Engelman says there are problems (17) over the world because of diseases, such as cholera, (18) are carried in water. Lack of water may also result (19) more international conflict. Countries may have to (20) for water in the future. Some countries now get sixty percent of their fresh water from other countries. This is true of Egypt, the Netherlands, Cambodia, Syria, Sudan, and Iraq. And the report says lack of water would affect the ability of developing to improve their economies. This is because new industries often need a large amount of water when they are beginning.