问题 选择题

下图为某同学用丝带扎紧上臂的示意图。发现丝带下方(近手指端)的血管①膨张,血管②变扁:丝带上方的血管 ③膨胀,血管  ④变扁下列有关叙述中,正确的是

A.血管①、④是动脉

B.血管②、③是静脉

C.血管①中血液的含氧量比血管③低

D.血管④中血液的含氧量比血管②高

答案

答案:C

题目分析:动脉是将血液从心脏送到全身各部分去的血管,血流方向是心脏→动脉,静脉是将血液从身体各部分送回心脏的血管,血流方向是心脏←静脉.用丝带扎紧上臂,发 现丝带上方(近心指端)的血管①膨胀,血管②变扁,丝带下方的血管③膨胀,血管④变扁,因此①④是动脉、②③是静脉,体静脉里流的是静脉血,静脉血含氧量 较低,体动脉里流的是动脉血,动脉血含氧量较高,因此血管④中血液含氧量比血管②高,血管③中血液含二氧化碳量比血管①高。

点评:此题有一定的难度,解答此类题目的关键是先根据血流动的方向判断出血管名称。

阅读理解

阅读理解。

                                                              History has arrived

      Nine-year-old Barack Obama was looking through magazine. But the African-America boy was shocked by

a series of photos. The pictures were of a black man who destroyed his skin with chemicals that promised to

make him white.

     For the first time, the boy began to doubt who he was. "I stood in front of the mirror and wondered if

something was wrong with me," Obama said.

     However, now the boy who used to struggle with his identity doesn't see it as a problem any more, but an

advantage for his career. Last week, Obama made history by being elected as the first black president of the

US. He defeated John MaCain in a landslide (压倒性的) victory.

     Obama's story starts in opposite corners of the world. His white mother was born in the heartland of the

US. His black father grew up in a tiny village in Kenya. They met during in Hawaii, but his father left the family when Obama was just two years old and his mother moved to Indonesia.

     At 10, Obama moved back to live with his white grandparents in Hawaii where his sense that he didn't

belong grew. At his class a white boy asked Obama if his father ate people. Out of embarrassment, Obama lied

to his classmates that his father was prince, "I kept asking who I am and I ended up trying drugs and

drinking," Obama recalled.

     Things came to change after the young man made friends with those with a similar background at college.

Their experiences back in Africa helped Obama to finally face up to his African origin. He worked hard to

become a star at Harvard Law School and the third black senator (参议院) in US history.

     At the beginning of his campaign for the White House, few people viewed Obama favorably (赞同地).

Many doubted his unusual background, which left him neither "black" enough nor white enough.

     But Obama turned his pain of growing up into a tool to make Americans believe: "There is not a black

America, an Asian America. There's the United States of America."

     Barack Obama's victory is "a historic victory that promised change and overcame centuries of prejudice

(偏见). His success fulfilled Martin Luther King's dream that a man he judged not by the color of his skin, but

by the content of his character," wrote ABC news.

1. From the above passage we can know that Barack Obama was born in ______.

A. Kenya, Africa

B. Hawaii, the USA

C. Indonesia, Asia

D. an unknown city, in Latino America

2. He lied to his classmates that his father was prince because ______.

A. he felt ashamed of his African origin

B. he had unusual background- neither black nor white

C. his black father deserted him when he was very young

D. he didn't have the sense of belonging

3. Put the following things in order of time.

a. Obama is the third black senator(参议院) in US history

b. Obama's mother settled down in Indonesia with Barack Obama

c. Obama stood out among his classmates in Harvard Law School

d. Obama lived with his white grandparents in Hawaii

e. Obama's black father left him and his mother

A. c, d, a, b, e

B. e, d, b, c, a

C. d, b, a,e, c

D. e, b, d, c, a

4. What does the title "History has arrived" probably mean?

A. Barack Obama eventually defeated his white opponent, John MaCain in a landslide victory.

B. Barack Obama's victory has given blacks and other minorities a true national role model.

C. Barack Obama has become the first African-American President, overcoming centuries of prejudice.

D. Through his great efforts, Barack Obama became the third black senator in the US history.

选择题