问题 问答题 简答题

如图为A、B、C三类植物在晴朗夏季的光合作用日变化曲线,请据图分析并回答:

(1)A植物在夜间能产生ATP的场所有____________。该植物夜间能吸收CO2,却不能合成糖类等有机物的原因是____________。

(2)A植物在10~16时不吸收CO2的直接原因是____________此时____________(填“能”或“不能”)进行光合作用的碳反应。据图推测该植物生活在____________的环境中。

(3)C曲线与横坐标的交点代表的意义是____________。

答案

参考答案:

(1)细胞质基质和线粒体;没有光照,光反应不能进行,无法为碳反应提供NADPH和ATP

(2)气孔关闭;能;高温干旱

(3)C植物的光合作用速率等于呼吸作用速率

解析:

(1)A植物夜间无法进行光合作用,产生ATP的场所只有细胞质基质和线粒体。A植物夜间能吸收CO2,却不能合成糖类等有机物是因为没有光照,光反应不能进行,无法为碳反应提供NADPH和ATP。

(2)A植物在10~16时由于高温,气孔关闭,CO2吸收量降低,此时仍可以进行光合作用的碳反应,据图可推测该植物生活在高温干旱的环境中。

(3)C曲线与横坐标相交时,CO2吸收速率为0,此时C植物的光合作用速率等于呼吸作用速率。

阅读理解

第三部分:阅读理解(共13小题;每小题2分,满分26分)

请认真阅读下列短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项,并在答题纸上将该项涂黑。

A

America is a mobile society. Friendships between Americans can be close and real, yet disappear soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while — then no more. If the same two people meet again by chance, even years later, they pick up the friendship. This can be quite difficult for us Chinese to understand, because friendships between us flower more slowly but then may become lifelong feelings, extending (延伸) sometimes deeply into both families.

Americans are ready to receive us foreigners at their homes, share their holidays, and their home life. They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily.

Another difficult point for us Chinese to understand Americans is that although they include us warmly in their personal everyday lives, they don’t show their politeness to us if it requires a great deal of time. This is usually the opposite of the practice in our country where we may be generous with our time. Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend. We may take days off to act as guides to our foreign friends. The Americans, however, express their welcome usually at homes, but truly can not manage the time to do a great deal with a visitor outside their daily routine. They will probably expect us to get ourselves from the airport to our own hotel by bus. And they expect that we will phone them from there. Once we arrive at their homes, the welcome will be full, warm and real. We will find ourselves treated hospitably.

For the Americans, it is often considered more friendly to invite a friend to their homes than to go to restaurants, except for purely business matters. So accept their hospitality at home!

56. The writer of this passage must be ______.

A. an American      B. a Chinese     C. a professor       D. a student

57. Which of the following statements is TRUE according to the passage?

A. Friendships between Americans usually extend deeply into their families.

B. Friendships between Americans usually last for all their lives.

C. Americans always show their warmth even if they are very busy.

D. Americans will continue their friendships again even after a long break.

58. From the last two paragraphs we can learn that when we arrive in America to visit an American friend, we will probably be ______.

A. warmly welcomed at the airport      B. offered a ride to his home

C. treated hospitably at his home       D. treated to dinner in a restaurant

59. The underlined words  “generous with our time” in Paragraph 3 probably mean ______.

A. strict with time    B. serious with time   C. careful with time   D. willing to spend time

60. A suitable title for this passage would probably be “______”.

A. Friendships between Chinese      B. Friendships between Americans

C. Americans’ hospitality           D. Americans’ and Chinese’s views of friendships

单项选择题