闸阀有什么特点？

病历摘要：听神经瘤患者男，37岁，右耳听力丧失数月。查体：右耳听力丧失，视力正常，余神经体征阴性。行头颅MR平扫及增强检查。

1.诊断是什么？

Levi Strauss was born in Bavaria (巴伐利亚) in Europe in 1829. He emigrated（移居）to the United States of America when he was seventeen years old. His brothers sold cloth, and he worked for them even though he could not speak English very well. At this time many people were moving to California because gold was discovered there. Strauss went to look for gold, too.

Strauss took a lot of cloth with him to San Francisco. He thought that he could make tents out of the cloth and sell them to people working in the gold fields. But when he got there, he saw that people had a greater need for clothes than tents. Clothes did not last very long in the gold fields. At first Strauss made pants out of canvas（帆布）. They were very strong ---- much stronger than other pants. Soon everyone was wearing them , so he decided only to make pants. He opened a small store and made a lot of money from selling pants.

After a while, Strauss found a material even stronger than canvas. It came from a town in France called Nimes. The French called the material serge de Nimes, which means “cloth from Nimes”. The Americans called it denim. Strauss also bought some cloth from Genoa, a town in Italy. To Americans this name sounds like “jeans”, so they called his pants jeans. The cloth that Strauss used was always blue, so people also called his pants blue jeans and blue denims. Other people called them Levi’s. Levi Strauss jeans are some of the best-selling jeans in the world today. They last a long time and are very comfortable.

56. 小题1:When Levi Strauss went to San Francisco for the first time, he wanted to ______.

A．find a strong material to make pants

B．work for his brothers

C．make money by selling tents

D．open a store to make pants57. 小题2:In the beginning Strauss made pants from ______.

A．serge de Nimes

B．silk

C．denim

D．canvas58. 小题3:The name “jeans” was first used by ______.

A．Bavarians

B．Americans

C．Italians

D．Frenchmen59. 小题4:The story is about ______.

A．where cloth came from

B．the man who first made jeans

C．how to make lots of money

D．life on the gold fields

下列关于热化学反应的描述中正确的是（　　）

A．500℃、30MPa下，将0.5mol N₂和1.5molH₂置于密闭的容器中充分反应生成NH₃（g），放热19.3kJ，其热化学方程式为：

N₂（g）+3H₂（g）⇌2NH₃（g）△H=-38.6kJ•mol^-1

B．HCl和NaOH反应的中和热△H=-57.3 kJ•mol^-1，则H₂SO₄和Ca（OH）₂反应的中和热△H=2×（-57.3）kJ•mol^-1

C．CO（g）的燃烧热是283.0 kJ•mol^-1，则2CO₂（g）=2CO（g）+O₂（g）反应的△H=+2×283.0 kJ•mol^-1

D．1 mol甲烷燃烧生成气态水和二氧化碳所放出的热量是甲烷的燃烧热

行政组织内部行使最高决策权的制度设计，可以分为委员制、混合制和（）。

A.集权制

B.层级制

C.首长制

D.职能制

学校管理方法特性有哪些？