新托福阅读模拟试题及答案前篇
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新托福阅读模拟试题及答案前篇
对于一般准备参加托福考试的同学来说,最后一个月都会用做各种托福模拟题和真题的方法来准备托福考试。下面是智课小编为大家带来的一个新托福阅读模拟试题希望对大家能有所帮助,并最后附上参考答案。
Hormones in the Body
Up to the beginning of the twentieth century, the nervoussystem was thought to control all communication within thebody and the resulting integration of behavior. Scientists haddetermined that nerves ran, essentially, on electrical impulses.These impulses were thought to be the engine for thought,emotion, movement, and internal processes such as digestion.However, experiments by William Bayliss and Ernest Starling onthe chemical secretin, which is produced in the small intestinewhen food enters the stomach, eventually challenged that view.From the small intestine, secretin travels through the
bloodstream to the pancreas. There, it stimulates the release ofdigestive chemicals. In this fashion, the intestinal cells that
produce secretin ultimately regulate the production of differentchemicals in a different organ, the pancreas.
Such a coordination of processes had been thought to
require control by the nervous system; Bayliss and Starlingshowed that it could occur through chemicals alone. This
discovery spurred Starling to coin the term hormone to refer tosecretin, taking it from the Greek word hormon, meaning "toexcite" or "to set in motion." A hormone is a chemical producedby one tissue to make things happen elsewhere.
As more hormones were discovered, they were categorized,primarily according to the process by which they operated on thebody. Some glands (which make up the endocrine system)secrete hormones directly into the bloodstream. Such glandsinclude the thyroid and the pituitary. The exocrine system
consists of organs and glands that produce substances that areused outside the bloodstream, primarily for digestion. The
pancreas is one such organ, although it secretes some chemicalsinto the blood and thus is also part of the endocrine system.
Much has been learned about hormones since their
discovery. Some play such key roles in regulating bodily
processes or behavior that their absence would cause immediatedeath. The most abundant hormones have effects that are lessobviously urgent but can be more far-reaching and difficult totrack: They modify moods and affect human behavior, even somebehavior we normally think of as voluntary. Hormonal systemsare very intricate. Even minute amounts of the right chemicalscan suppress appetite, calm aggression, and change the attitudeof a parent toward a child. Certain hormones accelerate thedevelopment of the body, regulating growth and form; othersmay even define an individual's personality characteristics. Thequantities and proportions of hormones produced change withage, so scientists have given a great deal of study to shifts in theendocrine system over time in the hopes of alleviating ailmentsassociated with aging.
In fact, some hormone therapies are already very common. Acombination of estrogen and progesterone has been prescribedfor decades to women who want to reduce mood swings, suddenchanges in body temperature, and other discomforts caused bylower natural levels of those hormones as they enter middle age.
Known as hormone replacement therapy (HRT), the treatmentwas also believed to prevent weakening of the bones. At leastone study has linked HRT with a heightened risk of heart diseaseand certain types of cancer. HRT may also increase the likelihoodthat blood clots-dangerous because they could travel throughthe bloodstream and block major blood vessels-will form. Someproponents of HRT have tempered their enthusiasm in the faceof this new evidence, recommending it only to patients whosesymptoms interfere with their abilities to live normal lives.
Human growth hormone may also be given to patients whoare secreting abnormally low amounts on their own. Because ofthe complicated effects growth hormone has on the body, suchtreatments are generally restricted to children who would bepathologically small in stature without it. Growth hormone
affects not just physical size but also the digestion of food andthe aging process. Researchers and family physicians tend to
agree that it is foolhardy to dispense it in cases in which the risksare not clearly outweighed by the benefits.
27. The word engine in the passage is closest in meaning to
(A) desire
(B) origin
(C) science
(D) chemical
28. The word it in the passage refers to
(A) secretin
(B) small intestine
(C) bloodstream
(D) pancreas
29. The word spurred in the passage is closest in meaning to
(A) remembered
(B) surprised
(C) invented
(D) motivated
30. To be considered a hormone, a chemical produced in thebody must
(A) be part of the digestive process
(B) influence the operations of the nervous system
(C) affect processes in a different part of the body
(D) regulate attitudes and behavior
31. The glands and organs mentioned in paragraph 3 arecategorized according to
(A) whether scientists understand their function
(B) how frequently they release hormones into the body
(C) whether the hormones they secrete influence the agingprocess
(D) whether they secrete chemicals into the blood
Paragraph 3 is marked with an arrow [→]
32. The word key in the passage is closest in meaning to
(A) misunderstood
(B) precise
(C) significant
(D) simple
33. The word minute in the passage is closest in meaning to
(A) sudden
(B) small
(C) changing
(D) noticeable