Question

【题目】Do you want to know how and why a fall leaf changes color? We first have to understand what leaves are and what they do.

Leaves are the world's food factories. Plants take water from the ground through their roots and take CO2 from the air. Plants use sunlight to turn water and CO2 into glucose(葡萄糖), a kind of sugar. Plants use it as food for energy and growing.

A chemical called “chlorophyll” in the leaves gives plants their green color. As summer ends and autumn comes, the days get shorter and shorter, and trees “know” to begin getting ready for winter.

During winter, there is not enough sunlight or water. Trees rest during this time and live on the food they store during the summer. They begin to shut down their foodmaking factories. As the green chlorophyll disappears from the leaves, we begin to see yellow and orange leaves.

The bright reds and purples we see in leaves are made mostly in autumn. In some trees, like maples(枫树), sunlight and the cool nights of autumn turn the glucose in the leaves into a red color. And we can enjoy the beautiful red leaves during autumn.

【1】Which should be in the box?

sunlight＋＋CO2→glucose

A. air B. sugar C. water

【2】The underlined word “chlorophyll” means “ ”．

A. 蛋白质 B. 脂肪 C. 叶绿素

【3】The leaves turn yellow because they are short of .

A. sunlight and water

B. glucose and energy

C. water and CO2

【4】Which of the following is NOT true?

A. When autumn comes, the days get shorter and shorter.

B. Trees begin to stop making food in summer.

C. During winter some of the yellow and orange colors are still in the leaves.

Answer 1

【答案】

【1】 C

【2】 C

【3】 A

【4】 B

【解析】

短文大意：叶子是世界食品厂。植物通过自己的根吸收地上的水和空气中的CO2。植物利用阳光将水和CO2转化成葡萄糖。植物用它作为能源和粮食。

【1】细节理解题。题干句意：Which should be in the box？sunlight＋＋CO2→glucose哪个应该在方框里？选项A. air 空气。B. sugar糖。C. water水。结合原文信息，根据文中第二段Plants take water from the ground through their roots and take CO2 from the air. Plants use sunlight to turn water and CO2 into glucose, a kind of sugar.植物通过根部从地面吸收水分，从空气中吸收二氧化碳。植物利用阳光将水和二氧化碳转化为葡萄糖,一种糖可知正确答案为：C

【2】词义猜测题。题干句意：The underlined word “chlorophyll” means “ ”．带下划线的单词叶绿素的意思是 。结合原文信息，根据文中第三段gives plants their green color.赋予植物绿色。可知，该词的意思是叶绿素，故正确答案为：C

【3】细节理解题。题干句意：The leaves turn yellow because they are short of .树叶变黄是因为他们缺少 。选项A. sunlight and water阳光和水。B. glucose and energy葡萄糖和能量。C. water and CO2 水和二氧化碳。结合原文信息，根据文中第四段During winter, there is not enough sunlight or water. Trees rest during this time and live on the food they store during the summer. They begin to shut down their food making factories. As the green chlorophyll disappears from the leaves, we begin to see yellow and orange leaves.在冬天，没有足够的阳光和水。树木在这段时间休息，靠夏天储存的食物为生。他们开始关闭他们的食品制造工厂。当绿色的叶绿素从叶子上消失时，我们开始看到黄色和橙色的叶子。可知正确答案为：A

【4】推理判断题。题干句意：Which of the following is NOT true？下列哪项是不正确的？选项A. When autumn comes, the days get shorter and shorter.当秋天来临时，白天变得越来越短。B. Trees begin to stop making food in summer.夏天树木开始停止生产食物。

C. During winter some of the yellow and orange colors are still in the leaves.在冬天，一些黄色和橙色仍然在树叶中。结合原文信息，通读整篇文章，可知B不正确，故答案为：B