英语每日一练

　　We tend to think of plants as the furniture of the natural world. They don’t move they don’t make sounds; they don’t seem to respond to anything—at least not very quickly. But as is often the case, our human view of the world misses quite a lot. Plants talk to each other all the time. And the language is chemical.

　　Over the years scientists have reported that different types of plants, from trees to tomatoes, release compounds into the air to help neighboring plants. These chemical warnings all have the same purpose—to spread information about one plant’s disease so other plants can defend themselves. But exactly how plants receive and act on many of these signals is still mysterious.

　　In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offer some explanations. They have identified one chemical message and traced it all the way from release to action.

　　The scientists looked at tomato plants infested (侵害) by common pest, the cutworm caterpillar (毛毛虫). To start out, they grew plants in two plastic compartments connected by a tube. One plant was infested and placed upwind and the others were uninfested and placed downwind. The downwind plants were later exposed to the cutworm caterpillar. The results showed that plants that had previously been near sick neighbors were able to defend themselves better against the caterpillar.

　　The researchers also studied leaves from exposed and unexposed plants. They found one compound showed up more often in the exposed plants. The substance is called Hex Vic. When the scientists fed Hex Vic to cutworms, it knocked down their survival rate by 17%. The scientists identified the source of Hex Vic, and sprayed it lightly over healthy plants. Those plants were then able to start producing the caterpillar-killing Hex Vic. Researchers confirmed that uninfested plants have to build their own weapon to fight off bugs and diseases. How do they know when to play defense? They are warned first by their friendly plant neighbors.

　　It is a complex tale, and it may be happening in more plant species than tomatoes. It may also be happening with more chemical signals that are still unknown to us. For now though, we know that plants not only communicate, they look out for one another.

　　1.What does the author try to emphasize Paragraph 1?

　　A. How plants communicate is still a mystery.

　　B. Enough attention has been paid to plant talk.

　　C. Plants are the furniture of the natural world.

　　D. Plants can communicate with each other.

　　2.According to Paragraph2, what remains unknown is __________.

　　A. how plants receive and handle the signals from their neighbors

　　B. why plants spread chemical information to their neighbor

　　C. how many types of plants release compounds into the air

　　D. whether plants send chemical warnings to their neighbors

　　3. The tomato plants in the experiment were __________.

　　A. placed separately but connected through air

　　B. exposed to different kinds of pests

　　C. exposed to the pest at the same time

　　D. placed together in a closed compartment

　　4.The experiment shows that the infested plant helps its neighbors by __________.

　　A. making more Hex Vic to attract the pest

　　B. releasing Hex Vic into the air to warn them

　　C. letting them know how to produce Hex Vic

　　D. producing enough Hex Vic to kill the pest

　　5.What may be the best title for the passage?

　　A. Survival of Plants

　　B. Plant World

　　C. Talking Plants

　　D. Plant Bug Killer

　　————————————

　　正确答案

　　1.【答案】D

　　【考点】细节推断

　　【解析】20世纪70年代之前，许多的大学运行“代替父母”体系的原因是什么。

　　在文章第一段前两句我们可以找到答案：在20世纪70年代之前，大学生都被当作孩子对待。因此许多大学运行“代替父母”这一体系。因此，此题选D项“大学生因为太年轻而被当成孩子对待”。

　　【误项排除】A项“他们能够代替学生的父母”，B项“为了孩子的利益，孩子的父母让学校这么做的”，C项“这是英国大学的一个传统”，这三项不符合题意。

　　2.【答案】A

　　【考点】细节推断

　　【解析】1913年戈特对伯里亚学院的诉讼案中谁胜出了?

　　在文章第二段第两句：多年以来，美国法庭在案子中支持“代替父母”方，比如1913年戈特对伯里亚学院的诉讼案。而“代替父母”方指的是学校。因此，此题选A项“伯里亚学院”。

　　【误项排除】B项“戈特”，C项“这是一例双赢案件”，D项“学生”，这三项不符合题意。

　　3.【答案】C

　　【考点】语义推断

　　【解析】第五段“dissent”一词最可能指的是什么。

　　在文章第五段第一句：但是在20世纪60年代，学生开始抗议类似的规定和约束。可知学生对此有异议。因此，此题选C项“强烈的异议”。

　　【误项排除】A项“极端行为”，B项“违反法律”，D项“坏事”，这三项不符合题意。

　　4.【答案】C

　　【考点】细节推断

　　【解析】1960年法院判决阿拉巴马州立大学怎么样?

　　在文章第六段第一句：1960年，阿拉巴马州立大学开除了六名参与公民权利示威的学生。学生将学校告上法庭并获得胜诉。可知学生将学校告上法庭的原因是其过分干涉其公民权利。因此，此题选C项“不应该干涉学生的日常生活”。

　　【误项排除】A项“无权开除学生”违背常识，B项“开除学生是合理的”，D项“应该支持公民权利示威”，这三项不符合题意。

　　5.【答案】B

　　【考点】语义推断

　　【解析】加里·迪克斯坦认为，“直升机父母”是什么样的父母?

　　在文章最后一段倒数第二句：加里·迪克斯坦说，这些父母可能会盘问孩子的决定，特别是关于安全问题和学习成绩。因此，此题选B项“密切关注孩子的生活和学习”。

　　【误项排除】A项“不放心学校管理者”，C项“不像以前那样关心孩子的教育情况”，D项“对孩子的教育有不同的观点”，这三项不符合题意。