信噪比越小越好。

下列各项不属于生命现象的是（   ）

A．牛在山坡上吃草

B．蝌蚪经过发育长成青蛙

C．北风吹，雁南飞

D．铁存放一段时间会生锈

下列句子中，加点的成语使用恰当的一句是（ ）

Ａ．十多年来，刘德华、张学友、郭富城、黎明在香港歌坛上鼎足而立。

B． 经济适用房制度本是一项利民、为民的民心工程，如果在实践中走了样，让本来惠及广大中低收入群

体的经济适用房成为新的奢侈，就只能让百姓望而却步。

Ｃ.美国政府在台湾问题上的危言危行，只能搬起石头砸自己的脚。

Ｄ．因为缺乏位置感，他们根本就不关心老百姓的疾苦，在他们看来，平民意识犹如一块一文不名的破布。

II. 阅读理解（Reading comprehension）（共20小题；选择题5小题，每小题1分；非选择题15小题，每小题2分，计35分）

A) 选择题：阅读下面的短文，根据文意从每题所给的四个选项（A、B、C 和D）中，选出能回答所提问题或完成所给句子的最佳选项。(Read the following passage which is followed by five questions or unfinished statements. For each of them there are four choices marked A, B, C and D. Choose the one that fits best according to the passage.)

Mexic Past and Present

Hundreds of years ago, Native-American tribes lived in Mexico. The Aztecs built beautiful cities. They had a calendar (历法) and a written  language. However, the Spanish destroyed the Aztecs in 1521. For the next 300 years, Spain ruled over Mexico. That's why Mexicans speak Spanish.

Every September 16 the Mexican people hold a celebration in Mexico City, their country's capital. It is their Independence Day. On that date in 1821 they told Spain they would no longer be ruled.

Breaking free from Spain caused a war. When it was over, the Mexicans had their own government. They made their own laws.

Today America and Mexico are friends, but it wasn't always that way. President James Polk wanted America to reach from the Atlantic Ocean to the Pacific Ocean. He tried to buy what is now the American southwest from Mexico. Mexico would not sell. So from 1846 to 1848 Mexico and America fought a war to ascertain where their borders would be. When the war ended, Mexico had lost a lot of land. Now the Rio Grande River forms the border between the two nations. America is on the north side of the river. Mexico is on the south side.

Mexico has mountains and a hot, dry climate. Crops can grow on only a small part of the land. Still, Mexicans grow much of the coffee, oranges, and sugar used in the US. Mexicans have influenced building styles in southwestern US and added words such as patio and canton to American English. Americans also enjoy eating many Mexican foods like burritos, tacos, tortillas, and tamales.

46. According to the passage, what happened second on a historical timeline?

A. Mexicans declared their independence from Spain.

B. The Spanish ruled Mexico.

C. The Aztecs lived in Mexico.

D. Americans fought a war with Mexico.

47. The passage says that President Polk wanted ________.

A. the US to expand its borders to the Pacific Ocean

B. Mexico to change its Independence Day to July 4th

C. Mexico to become one of the states of the Union

D. Americans to adopt the Mexican language

48. Another word for the underlined word “ascertain” is ________.

A. inspect      B. discover     C. change      D. determine

49. Mexicans have the following influences on America EXCEPT ________.

A. building styles         B. vocabulary

C. clothes                 D. food

50. Before the Aztecs were conquered, these Native Americans probably ________.

A. didn't speak Spanish     

B. couldn't read or write any language

C. didn't have tools          

D. didn't understand the concept of time

分析企业盈利能力时，应当排除以下项目（）。

A.证券买卖等非正常经营项目

B.已经或将要停止的营业项目

C.重大事故或法律更改等特别项目

D.会计准则或财务制度变更带来的累积影响

E.大量地使用现金结算的销售项目

怎样正确的拆卸轴承？