R-101检漏的方法。

用质数积的形式表示：42=（    ）×（    ）×（    ）。

190.168.2.56属于下列哪一类IP地址( )

A．A类

B．B类

C．C类

D．D类

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

黄土高原大部分位于我国地势三级阶梯中的[ ]

A．第一级阶梯

B．第二级阶梯

C．第三级阶梯

D．第一级阶梯与第二级阶梯的交界处

当代社会研究的主要层次不包括（）

A、宏观层次

B、个人层次

C、微观层次

D、社会单位层次