You should try to （ ）your ambition and be more realistic.
A.reserve B.restrain C.retain D.reclaim
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（ ）, police would not prosecute you.
A.Provided that you cooperated with us B.Provided that you will cooperate with us C.Provided that you have cooperated with us D.Provided that you would cooperate with us
He argues that he would not want (A) his children have to suffer (B) hardship or not be (C) socially acceptable because of lack of money (D).
There are two main things that make aircraft engineering difficult: the need to make every component as reliable as possible and the need to build everything as light as possible. The fact that an airplane is up in the air and cannot stop if anything goes wrong, makes it perhaps a matter of life and death that its performance is absolutely dependable.Given a certain power of engine, and consequently a certain fuel consumption, there is a practical limit to the total weight of an aircraft that can be made to fly. Out of that weight as much as possible is wanted for fuel, radio navigational instruments, passenger seats, or freight room, and of course, the passengers and aircraft themselves. So the structure of the aircraft has to be as small and light as safety and efficiency will allow. The designers of it must calculate the normal load that each part will bear. This specialist is called the "stress man". He takes account of any unusual stress that may be put on the part as a precaution against errors in manufacture, accident damage, etc.The stress man's calculations go to the designer of the part, and he must make it as strong as the stress man say is necessary. One or two samples are always tested to prove that they are as strong as the designer intended. Each separate part is tested, and then the whole assembly —for example, a complete wing, and finally the whole airplane. When a new type of airplane is made, normally only one of the first three will be flown. Two will be destroyed on the ground in structural tests. The third one will be tested in the air.When a plane has passed all the tests it can get a government certificate of airworthiness, without which it is illegal to fly, except for test flying.Making the working parts reliable is as difficult as making the structure strong enough. The flying controls, the electrical equipment, the fire precautions, etc. must not only be light in weight, but must work both at high altitudes where the temperature may be below freezing point and in the hot air of an airfield in the tropics.To solve all these problems the aircraft industry has a large number of research workers, with elaborate laboratories and test houses and new materials to give the best strength in relation to weight are constantly being tested.1.The two main requirements of aircraft design are （ ）.2.The maximum possible weight of an aircraft is determined by （ ）.3.The stress man's job is to （ ）.4.The first three airplanes of a new type （ ）.5.All equipment in an aircraft must（ ）.
A.speed
Nearly four out of 10 Americans will be obese within five years if people keep packing on pounds at the current rate — putting their health at risk, says one of the nation’s top obesity researchers. Currently, about 31%, or about 59 million people, are obese, which is defined as roughly 30 or more pounds over a healthy weight. Almost 65% are either obese or overweight, 10 to 30 pounds over a healthy weight, which increases their chances of developing diabetes, heart disease, some types of cancer and a host of other health problems. The medical costs associated with treating these diseases will strain the health care system and economy in the years to come, experts say.Americans are gaining one to two pounds a year, says James Hill, director of the Center for Human Nutrition at the university of Colorado Health Sciences Center in Denver. Hill predicts that, at the current rate, 39% of Americans will be obese by 2008. He’s one of several national weight-loss experts who offer possible solutions to the obesity epidemic in Friday’s journal Science. This report comes on the heels of a landmark report in January that showed being obese shaves seven years off a person’s life, and just being overweight shortens a person’s life span by about three years. To stop gaining weight, people need to either burn 100 calories more a day with physical activity or eat 100 calories less every day, Hill says. They could cut back a little on portions, skip one soda or walk one extra mile a day, which would take about 15 to 20 minutes, he says. Other papers in Science address overweight and the role of Genetics. Jeffrey Friedman, a scientist at the Howard Hughes Medical Institute at Rockefeller University, says basic differences in people’s genetics may partly explain why some remain lean in the current environment of fast food and huge portion sizes, while others are hundreds of pounds overweight is largely attributable to a set of genes, which compose a powerful physiological system that maintains consistency in weight in each individual.The human body has complex biological systems that include hunger and appetite hormones that make losing weight and keeping it off very difficult, he says. For instance, when people lose weight, levels of the hormone drop, which makes them, feel hungry and possibly slows down their metabolism, he says.Xavier Pi-Sunyer, director of the Obesity Research Center and chief of endocrinology at St. Luke’s Roosevelt Hospital in New York, says health professionals, including doctors and nurses, need to have better training on how to treat obesity and spend more time helping patients lose weight and keep it off. “Weight loss is difficult, but possible to attain,” Pi-Sunyer says. “Weight maintenance is harder but also possible.”
1.Which of the following is true according to the passage?2.Which of the following is not mentioned as a likely result of obesity?3.Friedman suggests that（ ）.4.To lose weight, Doctor Hill advises overweight people to （ ）.5.It is implied in the passage that losing weight is difficult because（ ）.
A.Experts have found no effective cure for obesity so far. B.Obesity rate could reach nearly 40% in America in five years. C.Obesity is defined as 10 to 30 pounds over a healthy weight. D.Obesity is seen as posing no serious threat to people's health.问题2： A.Earlier death. B.Cancer and other diseases. C.Pressure on the current health care system. D.Disorder in hormone levels.问题3： A.obesity is really caused by people's genetics B.the environment plays no part in making people obese C.both genetic and environment factors contribute to obesity D.losing weight will cause disorder in hormone levels问题4： A.stop drinking soda B.take up physical exercises C.turn to low-calorie diets D.all of above问题5： A.obese people can rarely resist the temptation of eating more B.biological factors are at work when people gain weight C.modern people are subjected to the constant pressure of work D.improvement on people's living standard cannot be held back（ ）, the old man had a sharp ear for even the slightest sound.
A.Blind as he was B.As he was blind C.As blind as he was D.In spite that he was blind
