课程推荐
学校活动
托福口语黄金80题 | 西安托福学习TPO9(六)
2019-08-29 16:57
来源:新东方网整理
作者:
task6题目 Listening Part:
Listen to part of a lecture in a biology class.
(female) We all know that insects like to eat plants. But some plants are able to develop ways to protect themselves from insects. Today I’m gonna talk about some ways plants defend themselves.
Now, some plants have physical features that prevent insects from landing on them. Like the passion plant, for ex ample, its leaves hav e little spiky hairs all over them. They’re like spikes, sticking out of the plant that are so numerous and dense that they prevent insects from landing on the leaves. Basically there’re just no room for the insects to land. And since insects can’t land on the leaves they can’t eat them. So the little hairs serve as a physical feature that help protect passion plant from insects.
All right! But other plants protect themselves using chemical defenses, like the potato plant. The potato plant is able to release a chemical throughout its leaf system whenever an insect attacks it, starts eating the leaf. So, say an insect starts eating a potato plant’s leaf, that will cause the plant to react by releasing a chemical throughout its leaf system. The insect swallows this chemical as it eats. And this chemical discourages the insect from wanting to eat more of the plant. How? Well, the substance makes the insect feel full, like it’s already had enough to eat. The insect no longer feels hungry so it stops eating the plant. So, b y emitting this chemical, the potato plant protects itself from insects.
Question:
Using points from the lecture, explain how the passion plant and the potato plant defend themselves from insects.
答案解析:
1. Reading key
(1.1) Main idea: two defensive strategies used by plants agains hungry insects
(1.2) Strategy 1: physical defense
(1.2.1) Example: passion fruit.
(1.2.2) Dense spiky little hair all over; that make it very difficult for the insects to land on them; no landing spots= no way to eat it
(1.3) Strategy 2: chemical defense
(1.3.1) Example: potato plant
(1.3.2) When being eaten by insects, it will emit a chemical that makes the insect feel full; the insect will stop eating it because it doesn’t feel hungry anymore
新东方小程序
查课程、找校区、找老师
版权及免责声明
①凡本网注明"稿件来源:新东方"的所有文字、图片和音视频稿件,版权均属新东方教育科技集团(含本网和新东方网) 所有,任何媒体、网站或个人未经本网协议授权不得转载、链接、转贴或以其他任何方式复制、发表。已经本网协议授权的媒体、网站,在下载使用时必须注明"稿件来源:新东方",违者本网将依法追究法律责任。
② 本网未注明"稿件来源:新东方"的文/图等稿件均为转载稿,本网转载仅基于传递更多信息之目的,并不意味着赞同转载稿的观点或证实其内容的真实性。如其他媒体、网站或个人从本网下载使用,必须保留本网注明的"稿件来源",并自负版权等法律责任。如擅自篡改为"稿件来源:新东方",本网将依法追究法律责任。
③ 如本网转载稿涉及版权等问题,请作者见稿后在两周内速来电与新东方网联系,电话:010-60908555。