Why do more and more people enjoy doing sports?_______

A . drive B . drives C . have drive

A . Right B . Wrong C . Not mentioned

A . they operate between 150 and 450 rpm B . they are connected to the propeller by gearing C . their smaller size and weight D . they can be connected directly to the propeller without gearing

A . was spoken B . is spoken C . spoke D . speak

M: I agree. People like bankcards because they offer greater safety and convenience than personal checks. Q: What can be inferred from the conversation？ (20) A．A merchant doesn't know the balance before completing a sale. B．No security system has yet been devised for personal checks. C．A personal check is secure at the check stand. D．The clerk can examine all the bankcards.

A．given in B．giving out C．giving away D．giving up

[A] Young people start working younger. [B] Recent graduates have entered the labor market. [C] More people must have tow jobs to support their families. [D] More women have entered the job market.

A．Y B．N C．NG

Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyze the smoking habits of twins. Her results, published in the Pharmacogenomics Journal, suggest that an individual's degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced. The Netherlands Twin Register is a voluntary database that contains details of some 7,000 pairs of adult twins (aged between 15 and 70) and 28,000 pairs of childhood twins. Such databases are prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register. The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes) but many of which have either no function, or an unknown function, To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behavior. pattern, it suggests that a particular version of a nearby gene is influencing that feature or behavior. Dr. Vink found four markers which seemed to be associated with smoking. They were on chromosomes 3, 6, 10 and 14, suggesting that at least four genes are involved. Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programs to be customized. Results such as Dr. Vink's must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain's problem may eventually become a thing of the past. Mark Twain is mentioned in the passage in order to show that A．he is a man with very Strong will power. B．it is easy to give up smoking temporarily. C．famous writers are often heavy smokers. D．only few people have his determination.

On Sundays and holidays, they liked to leave the cities and have a good time in the countryside. But not every family had a horse and wagon. People wanted and needed another form. of transportation. Inventors in many countries fried to meet this need. The first bicycle, which was very simple, appeared in 1790. People called it "the horse on wheels" .Then in 1861, with many improvements, bicycles became a practical form. of transportation. People liked hikes because they weren't as expensive as horses. They didn't need to build a special house to keep them in, and they didn't have to feed them. They could ride them in the city and in the countryside. Everybody in the family could ride—men and women, girls and boys. The main idea of this passage is ______. A．the bicycle has become a practical form. of transportation B．transportation has changed through time C．travelling in the countryside is difficult D．bicycle travel is easy in the city

A、They have at least shared the same environment within the mother. B、They have the same genes. C、They are usually raised in the same family. D、They have the same interests.

A．A.–I’m sure they will. B．B. because of C．C. so that D．D. even though E．E. as if

A．Organic food is usually more expensive than non-organic fooD． B．A wide variety of organic chocolate products are now available in stores C．Raw foods are enjoying increasing popularity, now that people are discovering how a raw-foods diet leaves you feeling and looking great． D．Fresh organic produce contains more vitamins, minerals, and enzymes than nonorganic produce