He studied at a famous college when he was young, （ ） contributed to his success in later life.
A.which B.it C.that D.what
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He studied at a famous college when he was young, （ ） contributed to his success in later life.
It has long been known that the rate of oxidative metabolism (the process that uses oxygen to convert food into energy) in any animal has a profound effect on its living patterns. The high metabolic rate of small animals, for example, gives them sustained power and activity per unit of weight, but at the cost of requiring constant consumption of food and water. Very large animals, with their relatively low metabolic rates, can survive well on a sporadic food supply, but can generate little metabolic energy per gram of body weight. If only oxidative metabolic rate is considered, therefore, one might assume that smaller, more active, animals could prey on larger ones, at least if they attacked in groups. Perhaps they could if it were not for anaerobic glycolysis, the great equalizer.Anaerobic glycolysis is a process in which energy is produced, without oxygen, through the breakdown of muscle glycogen into lactic acid and adenosine triphosphate (ATP), the energy provider. The amount of energy that can be produced anaerobically is a function of the amount of glycogen present ——in all vertebrates about 0.5 percent of their muscles’ net weight. Thus the anaerobic energy reserves of a vertebrate are proportional to the size of the animal. If, for example, some predators had attacked a 100-ten dinosaur, normally torpid, the dinosaur would have been able to generate almost instantaneously, via anaerobic glycolysis, the energy of 3,000 humans at maximum oxidative metabolic energy production. This explains how many large species have managed to compete with their more active neighbors: the compensation for a low oxidative metabolic rate is glycolysis.There are limitations, however, to this compensation. The glycogen reserves of any animal are good, at most, for only about two minutes at maximum effort, after which only the normal oxidative metabolic source of energy remains. With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted, via oxidative metabolism, by the liver into glucose, which is then sent (in part) back to the muscles for glycogen resynthesis. During this process the enormous energy debt that the animal has run up through anaerobic glycolysis must be repaid, a debt that is proportionally much greater for the larger vertebrates than for the smaller ones. Whereas the tiny shrew can replace in minutes the glycogen used for maximum effort, for example, the gigantic dinosaur would have required more than three weeks. It might seem that this interminably long recovery time in a large vertebrate would prove a grave disadvantage for survival. Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.The primary purpose of the passage is to（ ） .According to the author, a major limitation of anaerobic glycolysis is that it can（ ） .The passage suggests that the total anaerobic energy reserves of a vertebrate are proportional to the vertebrate’s size because（ ） .The author is most probably addressing which of the following audiences?Which of the following best states the central idea of the passage?
The animal dissection requirement of biology classes has been getting under the skin of students for generations, and there have always been some who asked to be excused from the requirement. Now, a growing number of technological alternatives are making it possible for students to swap that scalpel for a computer mouse. There are laws in nearly a dozen states — including California, Florida, New York — protecting a student’s choice to learn about animal anatomy sans scalpel. Some students choosing to opt out feel we should be kinder to our web-footed friends. Others are just queasy at the thought of rubbery frog bodies and the smell of formaldehyde.“Dissection is icky. There’s a yuck factor. ” admits Brian Shmaersky, a board member with the National Association of Biology Teachers. “And a teacher has to weigh the benefits with the cost of students being offended to the point that it interferes with learning. ”Virtual blades. So for cases in which a real dissection would be too slimy, it’s time to try some toad tech. While the first computer-based alternatives to dissection emerged in the 1980s, modem frog dissection software can be found at different websites. These software programs use creative clicking, high-powered zoom functions, and video clips to teach anatomy. Froguts software, for example, lets students trace incision lines with a computer mouse and snip through skin with a virtual blade. There are even sound effects like a “slish” for slicing frog flesh, or a “shwoosh” for pinning down skin flaps.(Schools currently pay about $ 300 for a one-year software license, though some organizations will lend programs out free of charge.) Earlier this year, a graduate student from Simon Fraser University in Vancouver designed the first-ever haptic (the Greek word for “touch”) frog dissection program, which uses a pen like tool to create a sensation similar to cutting into real flesh. The hand-held device connects to a computer, and students move the device through the air while watching the results of their actions on a computer screen.With Digital Frog — a popular program that’s had approximately 1, 500 frog demo downloads since January and is currently in use in 2, 000 schools — students can add or subtract those amphibious organs with a mere mouse click. They can then assess their learning with sporadic frog anatomy quizzes.“Repetition is helpful. The fact that a student can review sections of a program over and over again is important,” says Martin Stephens, vice president for animal research issues at the Humane Society of the United States. “In dissections, the animal’s organs are all shriveled and discolored. You look for things and can’t find them because body parts have changed drastically since the animal was killed. But on a computer screen, layers can be digitally peeled away. ” Other experts think the dissection technology has its limits. Gerry Wheeler, executive director of the National Science Teachers Association, says that artificial simulations don’t give as enriching an experience as the real thing. Still others worry the programs are depriving kids of experiential learning.1.The word “swap” (Line 3, Paragraph 1) most probably means（ ） .2.Some students ask to be excused from the requirement of biology classes because of the following reasons except that（ ）.3.Brian Shmaersky’ s statement implies that（ ）.4.The author’s attitude towards the toad tech can be said to be（ ） .
I wanted to buy a colour TV set this year, but my brother rejected the idea （ ）a trip to the beach.
Smell is the most direct of all the senses. It is thought to be the oldest sense in terms of human evolution, which may explain why smell is hard-wired into the brain. The olfactory nerve, which manages the perception of smells, is essentially an extension of the brain. The olfactory nerve provides a direct link from receptors at the top of the nose to the portion of the brain that controls memory, emotion, and behavior.The olfactory system detects certain airborne chemicals that enter the nose and then transmits this chemical information to the limbic system in the brain. The olfactory region at the upper end of each nostril is yellow, moist, and full of fatty substances. The shade of yellow indicates the strength of the sense of smell: the deeper the shade, the keener and more acute it is. Animals have a very strong sense of smell, so their olfactory regions are dark yellow to reddish brown, while those of humans are light yellow.When an odorous substance enters the nose, it binds to olfactory receptor cells, the neurons lining the yellow upper portion of the nasal cavity. Olfactory receptor cells contain microscopic hairs called cilia that extend into the layer of mucus coating the inside of the nose. Odor molecules diffuse into this region and are absorbed by the cilia of the olfactory receptor cells. What this means is that when we hold a rose to our nose and inhale, odor molecules float up into the nasal cavity, where they are absorbed by five million olfactory receptor cells. The receptor cells alert the olfactory nerve, which sends impulses to the brain’s olfactory bulb, or smell center. Thus, olfactory information about the rose enters the brain’s limbic system, where, in most of us, it stimulates a feeling of pleasure.The limbic system of the brain integrates memory, emotion, and behavior. The system is composed of a group of related nervous system structures that are the functional center of emotions such as anger, fear, pleasure, and sadness. The components of the limbic system are linked to the cerebral cortex, the part of the brain involved in complex learning, reasoning, and personality. The cerebral cortex makes decisions about the emotional content of these unique human qualities after “consulting” the limbic system and the other brain centers in processing and retrieving memories. It may, in turn, use memories to modify behavior.Scent may be the strongest trigger of memory and emotions. When we inhale a scent,receptors in the brain’s limbic center compare the odor entering our nose to odors stored in our memory. Along the way, memories associated with those odors are stimulated. A smell can be overwhelmingly nostalgic because it triggers powerful images and emotions. The waxy fragrance of crayons can instantly transport us to our second-grade classroom, or the scent of freshly mown grass can flood us with the joy of summer freedom. What we see and hear may fade quickly in short-term memory, but what we smell is sent directly to long-term memory.Smells can increase alertness and stimulate learning and retention. In one study, children memorized a word list, which was presented both with and without accompanying scents. The children recalled words on the list more easily and with higher accuracy when the list was given with scents than without, showing the link between smell and the ability to retain information. In another study,researchers examined how various smells can increase alertness and decrease stress. They found that the scent of lavender could wake up the metabolism and make people more alert. They also found that the smell of spiced apples could reduce blood pressure and avert a panic attack in people under stress.
1.Why does the author use the term “hard-wired” in describing the sense of smell and the brain?2.Of what significance is the color of the olfactory region at the upper end of each nostril?3.What happens when the cilia of the olfactory receptor cells absorb odor molecules?4. Why does the author mention “crayons” and “freshly mown grass” in Paragraph5?5.What can be inferred
I feel rather at a （ ）talking to her,because she’s so clever.