TOEFL IBT Reading Practice Test 71 from The Collection of TOEFL Reading Comprehension
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Reading Directions: This section measures your ability to understand academic passages in English.
The Reading section is divided into separately timed parts.
Most questions are worth 1 point, but the last question for each passage is worth more than 1 point. The directions for the last question indicate how many points you may receive. You will now begin the Reading section. There are three passages in the section. You should allow 20 minutes to read each passage and answer the questions about it. You should allow 60 minutes to complete the entire section.
- Reading Practice Test 72 from The Collection of TOEFL Reading Comprehension
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- Reading Practice Test 70 from The Collection of TOEFL Reading Comprehension
Cells cannot remain alive outside certain limits of temperature, and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only within a narrow range around 37℃; a departure of a few degrees from this value seriously impairs their functioning. Even though cells can survive wider fluctuations, the integrated actions of bodily systems are impaired. Other animals have a wider tolerance for changes of bodily temperature.
For centuries it has been recognized that mammals and birds differ from other animals in the way they regulate body temperature. Ways of characterizing the difference have become more accurate and meaningful over time, but popular terminology still reflects the old division into “warm – blooded” and “cold – blooded” species; warm – blooded included mammals and birds, whereas all other creatures were considered cold – blooded. As more species were studied, it became evident that this classification was inadequate. A fence lizard or a desert iguana-each cold – blooded-usually bas a body temperature only a degree or two below that of humans and so is not cold. Therefore the next distinction was made between animals that maintain a constant body temperature, called homeotherms, and those whose body temperature varies with their environment, called poikilotherms, But this classification also proved inadequate. because among mammals there are many that vary their body temperatures during hibernation. Furthermore, many invertebrates that live in the depths of the ocean never experience a change in the chill of the deep water, and their body temperatures remain constant.
The current distinction is between animals whose body temperature is regulated chiefly ‘by internal metabolic processes ” and those whose temperature is regulated by, and who get most of their heat from, the environment. The former are called endotherms, and the latter are called ectotherms. Most ectotherms do regulate their body temperature, and they do so mainly by locomoting to favorable sites or by changing their exposure to-external sources of heat. Endotherms (mainly mammals, and birds) also regulate their temperature by choosing favorable environments, but primarily they regulate their temperature by making a variety of internal adjustments.
1. What does the passage mainly discuss?
(A) Body temperatures of various animals
(B) The newest research on measuring temperature
(C) Methods of temperature reduction
(D) The classification of animals by temperature regulation
2. Which of the following terms refers primarily to mammals and birds?
3. In general, the temperature of endotherms is regulated
4. According to the passage, the chief way in which ectotherms regulate their temperature is by
(A) seeking out appropriate locations
(B) hibernating part of the year
(C) staying in deep water
(D) triggering certain metabolic processes
5. The word “sites” in line 25 is closest in meaning to which of the following?
6. Where in the passage does the author explain why some mammals are not homeotherms?
(A) Lines 7-8
(B) Lines 11-14
(C) Lines 16-18
(D) Lines 26-28