Question

【题目】Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.

Many trees and shrubs change color in fall. For years, scientists have worked hard to understand the changes that happen to them. They find that three factors 【1】 fall's colorful farewell — leaf pigments (色素), length of night, and weather. The timing of the color change is mainly regulated by the increasing length of night. None of the other 【2】influences, such as temperature, rainfall, food supply, are as unchanging as the 【3】increasing length of night during fall. As days grow shorter, and nights grow longer and cooler, biochemical 【4】 in leaves begin to paint the landscape with an explosion of colors. And Nature puts on one of its most splendid 【5】 of beauty.

The timing of the color change【6】 by species. Some species in southern forests can become vividly colorful in late summer while all other species are still vigorously green. Oaks put on their colors long after other species have already shed their leaves. These differences in timing among species seem to be genetically 【7】, for a particular species, whether on a high mountain or in warmer lowlands, will change color at the same time.

However, some species are evergreen. Pines, for example, are green all the year round because they have toughened up. They have developed over the years a needle-like or scale-like foliage (绿叶植物), which is【8】 with a heavy wax coating. And the liquid inside their cells contains cold-resistant elements. So the leaves of evergreens can safely withstand (经受住) all but the most 【9】winter conditions, such as those in the Arctic.

Answer 1

【答案】

【1】H

【2】C

【3】A

【4】B

【5】D

【6】F

【7】I

【8】E

【9】G

【解析】

这是一篇说明文。主要说明了科学家发现三个因素影响着秋天树叶的颜色变化——树叶色素、夜长和天气。颜色变化的时间主要受夜长变化的调节。不同的季节，树叶的颜色变化时间因物种而异，以及说明某些物种是常绿的原因。

【1】考查动词时态。句意：他们发现有三个因素影响着秋天树叶五彩缤纷的变化——树叶色素、夜长和天气。分析句子结构可知此处缺少谓语动词，且表示“影响”，描述客观事实用一般现在时，且主语为factors，故谓语动词用原形，故填influence。故选H。

【2】考查形容词。句意：其他的环境影响，如温度、降雨、食物供应等，都不如秋天里持续增加的黑夜那么一成不变。influences为名词需要形容词修饰，表示“环境影响”，故填environmental。故选C。

【3】考查副词。句意：其他的环境影响，如温度、降雨、食物供应等，都不如秋天里持续增加的黑夜那么一成不变。increase为动词需要副词修饰，表示“持续地”，故填steadily。故选A。

【4】考查名词。句意：随着白天变短，夜晚变长、变冷，树叶中的生化过程开始用爆炸般的颜色描绘风景。biochemical为形容词修饰名词，表示“生化过程”，且根据下文begin为原形可知应用复数形式。故填processes。故选B。

【5】考查名词。句意：大自然展现出它最壮丽的美丽。结合上文one of后跟名词复数形式，以及句意表示“展现”，故填displays。故选D。

【6】考查主谓一致。句意：颜色变化的时间因物种而异。本句中缺少谓语动词，结合句意表示“变化”，且描述客观事实用一般现在时，主语为The timing of the color change，谓语动词应用第三人称单数形式。故填varies。故选F。

【7】考查动词时态。句意：不同物种在时间上的差异似乎是遗传的，对于一个特定的物种来说，无论是在高山还是在温暖的低地，颜色都会同时发生变化。结合上文be genetically可知应填形容词，表示“遗传的”，故填inherited。故选I。

【8】考查固定短语。句意：这些年来，它们已经长出了针状或鳞状的叶子，上面覆盖着一层厚厚的蜡涂层。结合句意可知表示“覆盖”短语为be covered with。故填covered。故选E。

【9】考查形容词。句意：所以常青树的叶子可以安全的承受最严酷的冬季条件，比如北极地区。conditions为名词需要形容词修饰，表示“严酷的”，故填severe。故选G。