高考阅读理解限时训练(科普类)

高考阅读理解限时训练（科普类）

（附答案）

(一)

It turns out that overworking your brain with either physical or mental exercise may lower your ability to delay self-satisfaction. And that may set you up for poor choices in your self-care and finances.

A new study published Thursday in the journal Current Biology asked excellent endurance athletes to overtrain for three out of nine weeks, and compared them to a group who did a normal 9-week training program. Not only did those overworked athletes perform worse on a cycling test at the end of the overtraining, MRIs of their brains during behavioral tasks showed more exhaustion in the cognitive control part of the brain system. "Cognitive control in this situation is the capacity to maintain exercise despite things like muscle pain," said study author Bastien Blain, a research associate at University College London. "And what we found is that there is an intelligence factor involved in exercising and it has a limited capacity. You cannot use it forever."

In other words, your brain will burn out and affect your body's ability to exercise. But that's not all. Overworking that part of the brain also reduced the athletes' abilities to resist temptation of an immediate reward. "For example, they were asked whether they preferred $10 now or $50 in six months," Blain said. "And those who overtrained were more likely to

choose the immediate reward, which is interesting. It could provide a mechanism to explain why some athletes are using drugs to improve their performance.

One caution about the exercise study is that it only looked at endurance athletes, said. Dr. Marc-Andre Cornier, who is associate director of Colorado University's Anschutz Health and Wellness Center. "This is potentially very important for the higher end athlete who is overdoing it," Cornier said. "But does this have anything to do with the average Joe going to the gym? You can't conclude that from this study."

1. What does the underlined word "it" in the third paragraph refer to?

A. The brain system.

B. A limited capacity.

C. An intelligence factor.

D. The cognitive control.

2. Why did overworked athletes tend to choose the immediate reward?

A. Because they were too eager to succeed.

B. Because all parts of their brain were tired.

C. Because over training led to their bad decisions.

D. Because they took drugs to improve their performance.

3. What is the passage mainly about?

A. A study about self-satisfaction.

B. Negative effects of too much exercise.

C. The relation between brain and exercise.

D. Poor choices in people's self-care and finances.

4. What can we infer from the passage?

A. There is a limit to the brain.

B. Higher end athletes have great potential.

C. Top athletes may suffer from overtraining.

D. Delaying self-satisfaction results in better performance.

(二)

Many have long dreamed of being able to fly around as simply as riding a bicycle. Yet the safety and strength of a flying bike was always a big problem. Over the past decade, developments in technology have moved the dream of personal flying vehicles closer to reality. Now, two groups of inventors say such vehicles may be available very soon.

Grant Stapleton from Malloy Aeronautics says the Hoverbike, which is able to get in and out of small spaces very quickly, will be a truly personal flying vehicle. "It can be moved across continents very quickly because it can be folded and packed," he adds.

Mr. Stapleton says safety was the company's main concern when developing the Hoverbike. He says the designers solved the safety issue by using overlapping rotors (折叠旋翼) to power the vehicle. The company is testing both a one-third size model and a full-size prototype (原型) of the Hoverbike. Inventors say their Hoverbike will most likely be used first by the police and emergency rescue teams.

In New Zealand, the Martin Aircraft Company is also testing a full-size

prototype of its personal flying bike, called Jetpack. It can fly for more than 30 minutes, up to 1,000 meters high and reach a speed of 74 kilometers per hour.

Peter Coker is the CEO of Martin Aircraft Company. He said Jetpack "is built around safety from the start, " In his words, "reliability is the most important part of it. We have safety built into the actual structure itself, very similar to a Formula One racing car."

Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute (降落伞) that can be used should there be an emergency.

"It opens at a very low altitude and actually saves both the aircraft and the pilot in an emergency," he adds.

1. Which of the following words can best describe the Hoverbike?

A. Popular.

B. Fast.

C. Portable.

D. Fancy.

2. Who are expected to try the Hoverbike first?

A. People who dream of flying.

B. People who really love cycling.

C. People who design the bike.

D. People who serve public purposes.

3. According to the passage, which of the following is TRUE of the Jetpack?

A. It is very likely to get into an emergency.

B. It achieves reliability at the cost of speed.

C. It can fly at a relatively impressive height.

D. It resembles a Formula One racing car in structure.

4. What's the main concern shared by the two companies?

A. Design.

B. Speed.

C. Size.

D. Safety.

(三)

Mosquitoes have an extraordinary ability to target humans far away and fly straight to their unprotected skin. Regrettably, mosquitoes can do more than cause an itchy(发痒的)wound. Some mosquitoes spread several serious diseases, including Dengue, yellow fever and malaria. Over one million people worldwide die from these diseases each year. New research now shows how mosquitoes choose who to bite. Mosquitoes need blood to survive. They are attracted to human skin and breath. They smell the carbon dioxide gas, which all mammals breathe out. This gas is the main way for mosquitoes to know that a warm-blooded creature is nearby.

But mosquitoes also use their eyes and sense of touch. Michael Dickinson is a professor at the California Institute of Technology. His research shows how these small insects, with even smaller brains, use three senses to find a blood meal.

Michael Dickinson’s team used plumes—a material that rises into the