托福阅读真题练习：信息素的文本+题目+答案

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。

托福阅读文本：

Industrialization came to the United State after 1790 as North American entrepreneurs

increased productivity by reorganizing work and building factories. These innovations in

manufacturing boosted output and living standards to an unprecedented extent; the average per

capita wealth increased by nearly 1 percent per year — 30 percent over the course of a generation.

Goods that had once been luxury items became part of everyday life.

The impressive gain in output stemmed primarily from the way in which workers made goods,

since the 1790's, North American entrepreneurs — even without technological improvements —

had broadened the scope of the outwork system that made manufacturing more efficient by

distributing materials to a succession of workers who each performed a single step of the

production process. For example, during the 1820's and 1830's the shoe industry greatly expanded

the scale and extend of the outwork system. Tens of thousands of rural women, paid according to

the amount they produced, fabricated the "uppers" of shoes, which were bound to the soles by

wage-earning journeymen shoemakers in dozens of Massachusetts towns, whereas previously

journeymen would have made the entire shoe. This system of production made the employer a

powerful "shoe boss" and eroded workers' control over the pace and conditions of labor. However,

it also dramatically increased the output of shoes while cutting their price.

For tasks that were not suited to the outwork system, entrepreneurs created an even more

important new organization, the modem factory, which used power-driven machines and

assembly-line techniques to turn out large quantities of well-made goods. As early as 1782 the

prolific Delaware inventor Oliver Evans had built a highly automated, laborsaving flour mill

driven by water power. His machinery lifted the grain to the top of the mill, cleaned it as it fell into

containers known as hoppers, ground the grain into flour, and then conveyed the flour back to the

top of the mill to allow it to cool as it descended into barrels. Subsequently, manufacturers made

use of new improved stationary steam engines to power their mills. This new technology enabled

them to build factories in the nation's largest cities, taking advantage of urban concentrations of

inexpensive labor, good transportation networks, and eager customers.

托福阅读题目：

1. What is the passage mainly about?

(A) The difficulties of industrialization in North America

(B) The influence of changes in manufacturing on the growth of urban centers

(C) The rapid speed of industrialization in North America

(D) Improved ways of organizing the manufacturing of goods

2. The word "boosted" in line 3 is closest in meaning to

(A) ensured

(B) raised

(C) arranged

(D) discouraged

3. The word "scope" in line 9 is closest in meaning to

(A) value

(B) popularity

(C) extent

(D) diversity

4. The author mentions the shoe industry in the second paragraph to provide an example of how

(A) entrepreneurs increased output by using an extended outwork system

(B) entrepreneurs used technological improvements to increase output

(C) rural workers responded to "shoe bosses"

(D) changes in the outwork system improved the quality of shoes

5. All of the following are mentioned as effects of changes in the shoe industry during the 1820's

and 1830's EXCEPT

(A) an increase in the worker's dependence on entrepreneurs

(B) an increase in the wages paid to journeymen shoemakers

(C) a decline in the workers ability to control the speed of production

(D) a decrease in the price of shoes

6.All of the following are true of the outwork system EXCEPT

(A) It involved stages of production.

(B) It was more efficient than the systems used before 1790.

(C) It made many employers less powerful than they had been before.

(D) It did not necessarily involve any technological improvements.

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

(A) efficient

(B) productive

(C) self-employed

(D) progressive

8. According to the passage , how did later mills differ from the mills differ from the mill built by

Oliver Evans?

(A) They were located away from large cities.

(B) They used new technology to produce power.

(C) They did not allow flour to cool before it was placed in Barrels.

(D) They combined technology with the outwork system.

9. The word "it" in line 25 refers to

(A) water power

(B) machinery

(C) grain

(D) mill

10. The passage mentions which of the following as a result of improvements in factory

machinery?

(A) It become easier for factory' owners to find workers and customers.

(B) Manufacturers had to employ more highly skilled workers.

(C) The amount of power required for factories operate was reduced.

(D) Factories could operate more than one engine at a time.

11. The word "eager" in line 30 is closest in meaning to

(A) wealthy

(B) knowledgeable

(C) regular

(D) enthusiastic

托福阅读答案：

DBCAB CBBCA D

以上就是小编为大家整理的托福阅读100篇真题练习：美国工业发展的文本、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。