问题 选择题

与对应的静脉相比,动脉的主要特征是(  )

A.管内血液流速慢

B.常具有瓣膜

C.弹性大

D.管壁较薄

答案

动脉的功能是把心脏的血液输送到全身各处,静脉的功能是把全身各处的血液送回心脏,毛细血管是连通最小动脉和最小静脉,是血液与组织细胞之间进行物质交换的场所.

 管壁管腔血流速度
动脉最厚,弹性大较小最快
静脉较厚,弹性小较大较慢
毛细血管最薄,只有一层上皮细胞构成.非常细,只允许红细胞呈单行通过非常慢
故选C

阅读理解

阅读理解.

                                          A new Long March (长征)

     Twenty-one people from Hong Kong and the Chinese mainland began a new Long March on

October 15. They will walk about 8,000 kilometres from Ruijin, Jiangxi to Wuqi, Shanxi. They hope

to get 20.2 million yuan to build 101 schools and help poor children go back to school. They hope to

finish the march by August 16, 2012.

                                              The football team

     The Chinese under-17 football team is No. 1 in Asia. They won the Asian U-17 Championship

(亚洲U-17锦标赛) in Japan on Saturday. They beat the Democratic People's Republic of Korea

(朝鲜) by 1: 0. After 85 minutes, Wang Weilong got the only goal. They took the cup for the first

time in 12 years.

                                               Liu leaves China

     Chinese actor Liu Ye left for the US on Monday to make a film called Meteor (《流星》). He

is going to act with the Hollywood film star Meryl Streep. His former classmate Zhang Ziyi sent Liu

a message to encourage him. Liu was worried about his English, and worked hard on it before he left.

People know him from films like last year's "Mei Ren Cao".

1. From the news,we know that the twenty-one people began a new Long March to ______.

A. travel around China

B. visit some schools

C. teach poor children

D. get some money and help poor children go back to school

2. The second piece of news tells us ______.

A. Korea held this contest

B. the Chinese football team is No. 1 in South-East Asia

C. the Chinese under-17 football team won the world championship

D. the Chinese under-17 football team won the championship for the first time in 12years

3. Which of the paragraphs is about sports? ______

A. The 1st

B. The 2nd

C. The 3rd

D. The 3th and the 1st

单项选择题