2024年TOEFL阅读理解真题精选.docx
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1、2024年TOEFL阅读理解真题精选 为了让大家更好的打算托福考试,我给大家整理一些托福阅读真题,下面我就和大家共享,来观赏一下吧。 托福阅读真题1 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, whi
2、ch 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
3、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 usu
4、ally 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
5、 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
6、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 appreciat
7、e 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 s
8、exes, 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 gre
9、garious habits and sedentary nature, secrete an alarm pheromone when attacked that causes nearby aphids to respond by moving away. 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
10、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 (
11、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 wh
12、ich 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) che
13、mical 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
14、) 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 hig
15、hly 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 rel
16、atively complex in insects that (A) also communicate using sight and sound (B) live underground (C) prey on other insects (D) live in organized groups PASSAGE 95 ABCCB ADBAAD 托福阅读真题2 The Homestead Act of 1862 gave heads of families or individuals aged twenty-one or older the right to own 160 acres o
17、f public land in the western United States after five years of residence and improvement. This law was intended to provide land for small farmers and to prevent land from being bought for resale at a profit or being owned by large landholders. An early amendment to the act even prevented husbands an
18、d wives from filing separate claims. The West, land reformers had assumed, would soon contain many 160-acre family farms. They were doomed to disappointment. Most landless Americans were too poor to become farmers even when they could obtain land without cost. The expense of moving a family to the e
19、ver-receding frontier exceeded the means of many, and the cost of tools, draft animals, a wagon, a well, fencing, and of building the simplest house, might come to $1,000 a formidable barrier. As for the industrial workers for whom the free land was supposed to provide a safety valve, they had neith
20、er the skills nor the inclination to become farmers. Homesteaders usually came from districts not far removed from frontier conditions. And despite the intent of the law, speculators often managed to obtain large tracts. They hired people to stake out claims, falsely swear that they had fulfilled th
21、e conditions laid down in the law for obtaining legal title, and then deed the land over to their employers. Furthermore, 160 acres were not enough for raising livestock or for the kind of commercial agriculture that was developing west of the Mississippi. The national government made a feeble attem
22、pt to make larger holdings available to homesteaders by passing the Timber Culture Act of 1873, which permitted individuals to claim an additional 160 acres if they would agree to plant a quarter of it in trees within ten years. This law proved helpful to some farmers in the largely treeless states
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