托福阅读理解真题精选篇
托福阅读真题1
The smooth operation of an ant colony depends on ten to twenty different signals, most of which are pheromones (chemical signals triggering behavioral respons). It is estimated that red fire ants employ at least twelve different chemical signals. The simplest of the is the carbon dioxide from the respiration of an ant cluster, a chemical that acts as a pheromone to promote aggregation. Workers move toward a source of carbon dioxide, resulting in solitary ants moving to join a group. At the other extreme, the most complex of the fire ants' signals is probably colony odor, by which the workers of a particular colony or nest identify another worker as local or foreign. Each ant nest has its own odor as a result of its location, history, and local food supply. The resident ants pick up this odor on their bodies, so that ants of the same species, but from different nests, have different colony odors. This allows ants to identify intruders and maintain colony integrity.
Fire ants also make u of an alarm pheromone to alert workers to an emergency, and th
eir scouts lay down a trail pheromone as a guide during mass migrations. A fire ant queen emits a chemical signal that identifies her to the colony's workers. They respond by scurrying to gather around her. The decomposing corp of a dead ant also generates a signal, to which workers respond by eliminating the corp from the nest.
Ants provide examples of both public (accessible to other species) and private messages. One of their most important private messages concerns food, for a food source is worth keeping cret. Each species marks its trails with signals that are meaningless to others, so that an ant crossing a trail left by another ant species typically notices nothing. On the other hand, a cret signal to mark a dead body is unnecessary. Many kinds of ants perceive a natural decomposition product of dead incts as a signal to remove a corp. If an outsider recognizes this message and moves the body, no harm is done.
1. What aspect of ants does the passage mainly discuss?
监理会议纪要 (A) The relationship between the queen and the worker ants
孕妇吃什么补血 (B) Ways in which ants u chemical signals
(C) Methods ants u to identify food sources
(D) The importance of respiration in the production of ant pheromones
2. The phra smooth operation in line 1 is clost in meaning to
(A) daily activity
(B) effective functioning
(C) delicate balance
(D) permanent location
3. According to the passage , carbon dioxide rves which of the following functions for fire ants?
(A) It protects the queen.
(B) It attracts other ant species.
(C) It informs workers of possible danger.
(D) It encourages the ants to gather together.瘦脸的最好方法
4. The word cluster in line 4 is clost in meaning to
(A) organ
(B) activity
(C) group
(D) cycle
5. According to the passage , each nest has a distinct odor that allows its inhabitants to
(A) find the location of the nest in the dark
(B) distinguish worker ants from other ants
(C) distinguish foreign ants from resident ants
(D) signal other inhabitants when foreign ants attack
6. The word alert in line 13 is clost in meaning to
(A) allow
(B) transport
(C) warn
(D) provide
7. What is the role of pheromones in the mass migrations of ants?牡丹仙子的传说
(A) Pheromones are ud to create a trail that directs the ants during migrations.
(B) Pheromones signal the ants that the nest has been invaded and must be abandoned.
(C) Pheromones control the speed at which ants move from one location to another.
(D) Pheromones enable scouts to identify suitable areas for establishing a new nest.
8. The word scurrying in line 16 is clost in meaning to
(A) agreeing
(B) appearing
益反义词>如何退货 (C) competing
(D) rushing
9. The word others in line 21 refers to
(A) private messages
(B) species
(C) trails
(D) signals
10. Why does the author mention dead incts in line 23?
(A) To compare the social behaviors of ants with tho of other incts
安徽省中考时间 (B) To emphasize the dangers that all incts encounter
(C) To argue the superiority of ants over other incts
国画牡丹图片
(D) To indicate a behavior that is common among various kinds of ants
11. Which of the following terms is defined in the passage ?
(A) pheromones (line 2)
(B) colony integrity (lines 12)
(C) mass migrations (line 14)
(D) private messages (lines 18-19)
__ 86 BBDCC CADBD A
托福阅读真题2
Becau the low latitudes of the Earth, the areas near the equator, receive more heat than the latitudes near the poles, and becau the nature of heat is to expand and move, heat is transported from the tropics to the middle and high latitudes. Some of this heat is moved by winds and some by ocean currents, and some gets stored in the atmosphere in the form of latent heat. The term latent heat refers to the energy that has to be ud to convert liquid water to water vapor. We know that if we warm a pan of water on a stove, it will evaporate, or turn into vapor, faster than if it is allowed to sit at room temperature. We also know that if we hang wet clothes outside in the summertime they will dry faster than in winter, when temperatures are colder. The energy ud in both cas to change liquid water to water vapor is supplied by heat — supplied by the stove in the first ca and by the Sun in the latter ca. This energy is not lost. It is stored in water vapor in the atmosphere as latent heat. Eventually, the water stored as vapor in the atmosphere will conden to liquid again, and the energy will be relead to the atmosphere.
