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老托福阅读真题及答案:passage11

老托福阅读真题及答案:passage11为了帮助大家备考托福阅读,提高成绩,下面小编给大家带来老托福阅读真题及答案:passage 11,希望大家喜欢!老托福阅读真题及答案:passage 11Plants are subject to attack and infection by a remarkable variety of symbiotic species and have evolved a diverse array of mechanisms designed to frustrate the potential colonists. These can be divided into preformed or passive defense mechanisms and inducible or active systems. Passive plant defense comprises physical and chemical barriers that prevent entry of pathogens, such as bacteria, or render tissues unpalatable or toxic to the invader. The external surfaces of plants, in addition to being covered by an epidermis and a waxy cuticle, often carry spiky hairs known as trichomes, which either prevent feeding by insects or may even puncture and kill insect larvae. Other trichomes are sticky and glandular and effectively trap and immobilize insects.If the physical barriers of the plant are breached, then preformed chemicals may inhibit or kill the intruder, and plant tissues contain a diverse array of toxic or potentially toxic substances, such as resins, tannins, glycosides, and alkaloids, many of which are highly effective deterrents to insects that feed on plants. The success of the Colorado beetle in infesting potatoes, for example, seems to be correlated with its high tolerance to alkaloids that normally repel potential pests. Other possible chemical defenses, while not directly toxic to the parasite, may inhibit some essential step in the establishment of a parasitic relationship. For example, glycoproteins in plant cell walls may inactivate enzymes that degrade cell walls. These enzymes are often produced by bacteria and fungi.Active plant defense mechanisms are comparable to the immune system of vertebrate animals, although the cellular and molecular bases are fundamentally different. Both, however, are triggered in reaction to intrusion, implying that the host has some means of recognizing the presence of a foreign organism. The most dramatic example of an inducible plant defense reaction is the hypersensitive response. In the hypersensitive response, cells undergo rapid necrosis — that is, they become diseased and die —after being penetrated by a parasite; the parasite itself subsequently ceases to grow and is therefore restricted to one or a few cells around the entry site. Several theories have been put forward to explain the basis of hypersensitive resistance.1. What does the passage mainly discuss?(A) The success of parasites in resisting plant defense mechanisms(B) Theories on active plant defense mechanisms(C) How plant defense mechanisms function(D) How the immune system of animals and the defense mechanisms of plants differ2. The phrase "subject to" in line 1 is closest in meaning to(A) susceptible to(B) classified by(C) attractive to(D) strengthened by3. The word "puncture" in line 8 is closest in meaning to(A) pierce(B) pinch(C) surround(D) cover .4. The word "which" in line 12 refers to(A) tissues(B) substances(C) barriers(D) insects5. Which of the following substances does the author mention as NOT necessarily being toxic to the Colorado beetle?(A) resins(B) tannins(C) glycosides(D) alkaloids6. Why does the author mention "glycoproteins" in line 17?(A) to compare plant defense mechanisms to the immune system of animals(B) to introduce the discussion of active defense mechanisms in plants(C) to illustrate how chemicals function in plant defense(D) to emphasize the importance of physical barriers in plant defense7. The word "dramatic" in line 23 could best be replaced by(A) striking(B) accurate(C) consistent(D) appealing8. Where in the passage does the author describe an active plant-defense reaction?(A) Lines 1-3(B) Lines 4-6(C) Lines 13-15(D) Lines 24-279. The passage most probably continues with a discussion of theories on(A) the basis of passive plant defense(B) how chemicals inhibit a parasitic relationship.(C) how plants produce toxic chemicals(D) the principles of the hypersensitive response.正确答案:CAABD CADD托福阅读易错词汇的整理1) quite 相当 quiet 安静地2) affect v 影响, 假装 effect n 结果, 影响3) adapt 适应 adopt 采用 adept 内行4) angel 天使 angle 角度5) dairy 牛奶厂 diary 日记6) contend 奋斗, 斗争content 内容, 满足的context 上下文contest 竞争, 比赛7) principal 校长, 主要的 principle 原则8) implicit 含蓄的 explicit 明白的9) dessert 甜食 desert 沙漠 v 放弃 dissert 写论文10) pat 轻拍 tap 轻打 slap 掌击 rap 敲,打11) decent 正经的 descent n 向下, 血统 descend v 向下12) sweet 甜的 sweat 汗水13) later 后来 latter 后者 latest 最近的 lately adv 最近14) costume 服装 custom 习惯15) extensive 广泛的 intensive 深刻的16) aural 耳的 oral 口头的17) abroad 国外 aboard 上(船,飞机)18) altar 祭坛 alter 改变19) assent 同意 ascent 上升 accent 口音20) champion 冠军 champagne 香槟酒 campaign 战役21) baron 男爵 barren 不毛之地的 barn 古仓22) beam 梁,光束 bean 豆 been have 过去式23) precede 领先 proceed 进行,继续24) pray 祈祷 prey 猎物25) chicken 鸡 kitchen 厨房26) monkey 猴子 donkey 驴27) chore 家务活 chord 和弦 cord 细绳28) cite 引用 site 场所 sight 视觉29) clash (金属)幢击声 crash 碰幢,坠落 crush 压坏30) compliment 赞美 complement 附加物31) confirm 确认 conform 使顺从32) contact 接触 contract 合同 contrast 对照33) council 议会 counsel 忠告 consul 领事34) crow 乌鸦 crown 王冠 clown 小丑 cow 牛35) dose 一剂药 doze 打盹36) drawn draw 过去分词 drown 溺水托福阅读学术词汇的解析什么是学术词汇在托福阅读的课堂上,经常有学生对繁杂的学术词汇头疼不已。

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