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问题 计算题

瑞瑞同学家住楼上，最近正在装修房子，需要搬运装修材料，但有些材料由于楼道过窄不方便搬运，于是瑞瑞建议采用如图所示的滑轮组，这样站在地上就可以把材料运上楼.若某次搬运的材料重765N，被提升的高度为10m，人所用的拉力为450N求：

（1）请你帮助瑞瑞画出滑轮组的绕线示意图.

（2）用滑轮组提升材料时做的有用功是多少？

（3）该滑轮组的机械效率是多少？

答案

解：

（1）绕线示意图如图所示。

（2）W有=Gh=765N×10m=7650J

（3）η=W有/W总=Gh/Fs=G/2F=765N/2×450N=85﹪

单项选择题 A1型题

下列腧穴中通于阳跷脉的八脉交会穴是（）

A.足临泣

B.后溪

C.外关

D.申脉

E.列缺
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单项选择题

The China boom is by now a well-documented phenomenon. Who hasn’t (1) the Middle Kingdom’s astounding economic growth (8 percent annually), its mesmerizing (2) market (1.2 billion people), the investment ardor of foreign suitors ($40 billion in foreign direct investment last year (3) ) China is an economic juggernaut. (4) Nicholas Lardy of the Brookings Institution, a Washington D. C.-based think tank,

" No country has (5) its foreign trade as fast as China over the last 20 years. Japan (6) its foreign trade over a 20-year period; China’s foreign trade as quintupled. They’ve become the pre-eminent producer of labor-intensive (7) goods in the world " . But there’s been (8) from the dazzling China growth story—namely, the Chinese multinational. No major Chinese companies have (9) established themselves, or their brands, (10) the global stage. But as Haier shows, that is starting to change. (11) 100 years of poverty and chaos, of being overshadowed by foreign countries and multinationals, Chinese industrial companies are starting to (12) on the world.A new generation of large and credible firms has (13) in China in the electronics, appliance and even high-tech sectors. Some have reached critical mass on the mainland and are now (14) new outlets for their production—through exports and by building Chinese factories abroad, chiefly in Southeast Asia. One example: China’s investment in Malaysia (15) from $8 million in 2000 to $766 million in the first half of this year. (16) China’s export prowess, it will be years (17) Chinese firms achieve the managerial and operational expertise of Western and Japanese multinationals. For one thing, many of its best companies are still at least partially state-owned. (18) , China has a shortage of managerial talent and little notion of marketing and brand-building. Its companies are also (19) by the country’s long tradition of central planning, inefficient use of capital and antiquated distribution system, (20) makes building national companies a challenge.

（15）处填（）

A.rising

B.increasing

C.enhanced

D.soared
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