网站导航     在线客服  
全部
托福模考软件免费下载
   首页    托福   备考心经   托福资料   正文
学生选择在小站备考:30天 1634269名,今日申请8156人    备考咨询 >>

托福阅读真题练习:信息素的文本+题目+答案

2017年12月12日15:20 来源:小站整理
参与(0) 阅读(358)
摘要:托福阅读真题哪里有?大家平时备考托福阅读考试的时候都用的是哪些真题呢?除了TPO的托福阅读真题以外,大家进行托福阅读的练习大多数可能都是根据老托资料或者是课外资料来练习了。那么到哪里去找到托福阅读真题来进行练习呢?

托福阅读如何进行备考?除了大量的托福词汇储备以外,大家可能最需要的就是托福阅读真题的练习。那么除了TPO你还有哪些托福阅读真题进行练习呢?今天小编就为大家整理了托福阅读真题100篇:信息素的文本、题目以及答案,希望可以帮助到大家。

托福阅读真题练习:信息素的文本+题目+答案图1

托福阅读100篇真题练习汇总:http://toefl.zhan.com/tfziliao63739.html

托福阅读文本:

Pheromones are substances that serve as chemical signals between members of the same

species. They are secreted to the outside of the body and cause other individuals of the species to

have specific reactions. Pheromones, which are sometimes called "social hormones," affect a

group of individuals somewhat like hormones do an individual animal. Pheromones are the

predominant medium of communication among insects (but rarely the sole method). Some species

have simple pheromone systems and produce only a few pheromones, but others produce many

with various functions. Pheromone systems are the most complex in some of the so-called social

insects, insects that live in organized groups.

Chemical communication differs from that by sight or sound in several ways. Transmission is

relatively slow (the chemical signals are usually airborne), but the signal can be persistent,

depending upon the volatility of the chemical, and is sometimes effective over a very long range.

Localization of the signal is generally poorer than localization of a sound or visual stimulus and is

usually effected by the animal's moving upwind in response to the stimulus. The ability to

modulate a chemical signal is limited, compared with communication by visual or acoustic means,

but some pheromones may convey different meanings and consequently result in different

behavioral or physiological responses, depending on their concentration or when presented in

combination. The modulation of chemical signals occurs via the elaboration of the number of

exocrine glands that produce pheromones. Some species, such as ants, seem to be very articulate

creatures, but their medium of communication is difficult for humans to study and appreciate

because of our own olfactory, insensitivity and the technological difficulties in detecting and

analyzing these pheromones.

Pheromones play numerous roles in the activities of insects. They may act as alarm substances,

play a role in individual and group recognition, serve as attractants between sexes, mediate the

formation of aggregations, identify foraging trails, and be involved in caste determination. For

example, pheromones involved in caste determination include the "queen substance" produced by

queen honey bees. Aphids, which are particularly vulnerable to predators because of their

gregarious habits and sedentary nature, secrete an alarm pheromone when attacked that causes

nearby aphids to respond by moving away.

托福阅读题目:

1. What does the passage mainly discuss?

(A) How insects use pheromones to communicate

(B) How pheromones are produced by insects

(C) Why analyzing insect pheromones is difficult

(D) The different uses of pheromones among various insect species

2. The word "serve" in line 1 is closest in meaning to

(A) improve

(B) function

(C) begin

(D) rely

3. The purpose of the second mention of "hormones" in line 4 is to point out

(A) chemical signals that are common among insects

(B) specific responses of various species to chemical signals

(C) similarities between two chemical substances

(D) how insects produce different chemical substances

4. The word "sole" in line 6 is closest in meaning to

(A) obvious

(B) best

(C) only

(D) final

5. The passage suggests that the speed at which communication through pheromones occurs is

dependent on how quickly they

(A) lose their effectiveness

(B) evaporate in the air

(C) travel through the air

(D) are produced by the body

6. According to the passage , the meaning of a message communicated through a pheromone may

vary when the

(A) chemical structure of the pheromone is changed

(B) pheromone is excreted while other pheromones are also being excreted

(C) exocrine glands do not produce the pheromone

(D) pheromone is released near certain specific organisms

7. The word "detecting" in line 23 is closest in meaning to

(A) controlling

(B) storing

(C) questioning

(D) finding

8.According to paragraph 2, which of the following has made the study of pheromones difficult?

(A) Pheromones cannot be easily reproduced in chemical laboratories.

(B) Existing technology cannot fully explore the properties of pheromones.

(C) Pheromones are highly volatile.

(D) Pheromone signals are constantly changing.

9. The word "They" in line 24 refers to

(A) pheromones

(B) roles

(C) activities

(D) insects

10. The word "sedentary" in line 29 is closest in meaning to

(A) inactive

(B) inefficient

(C) unchangeable

(D) unbalanced

11. Pheromone systems are relatively complex in insects that

(A) also communicate using sight and sound

(B) live underground

(C) prey on other insects

(D) live in organized groups

托福阅读答案:

ABCCBADBAAD

以上就是小编为大家整理的托福阅读100篇真题练习:信息素的文本、题目以及答案,大家在托福阅读考试进行备考的过程当中也可以拿这些题目来进行练习,相信对于你的托福阅读考试成绩提升会很有帮助。最后,小编预祝大家托福考试能取得理想的成绩。

感觉茅塞顿开?现在就去练练手吧!
大家都在学

看完这篇文章有何感觉?已经有0人表态,0%的人喜欢

相关文章

110分托福大神力荐!搞定听说读写这些材料必备 托福加试全破解 轻松搞定加试这件小事儿 独家秘籍 独门绝招 必备宝书 3步轻松突破托福8000词 三个锦囊 解密托福阅读提速之道 【小站原创】TPO44托福阅读文本及答案解析(Seagra... 托福考试一周备考计划——让你7天搞定托福阅读 2017托福考情预测备考资料推荐-小站托福 最新托福独立写作完整版题目+范文汇总
【小站托福官网】TOEFL托福考试为您提供最新托福备考资料,托福机经预测,托福听力、口语、阅读、写作、词汇真题下载,更有toefl模拟考试、托福报名、托福培训等特色服务。
版权申明| 隐私保护| 意见反馈| 联系我们| 关于我们| 网站地图| 最新资讯

©{beginDate}-{endDate} ZHAN.com All Rights Reserved. {hbText}