Q26: Healthy lungs produce a natural antibiotic that protects them from infection by routinely killing harmful bacteria on airway surfaces. People with cystic fibrosis, however, are unable to fight off such bacteria, even though their lungs produce normal amounts of the antibiotic. The fluid on a0.irway surfaces in the lungs of people with cystic fibrosis has an abnormally high salt concentration; accordingly, scientists hypothesize that the high salt concentration is what makes the antibiotic ineffective.
Which of the following, if true, most strongly supports the scientists’ hypothesis?
- When the salt concentration of the fluid on the airway surfaces of healthy people is raised artificially, the salt concentration soon returns to normal.
- A sample of the antibiotic was capable of killing bacteria in an environment with an unusually low concentration of salt.
- When lung tissue from people with cystic fibrosis is maintained in a solution with a normal salt concentration, the tissue can resist bacteria.
- Many lung infections can be treated by applying synthetic antibiotics to the airway surfaces.
- High salt concentrations have an antibiotic effect in many circumstances.
It is true of both men and women that those who marry as young adults live longer than those who never marry. This dose not show that marriage causes people to live longer, since, as compared with other people of the same age, young adults who are about to get married have fewer of the unhealthy habits that can cause a person to have a shorter life, most notably smoking and immoderate drinking of alcohol.
Which of the following, if true, most strengthens the argument above?
- Marriage tends to cause people to engage less regularly in sports that involve risk of bodily harm.
- A married person who has an unhealthy habit is more likely to give up that habit than a person with the same habit who is unmarried.
- A person who smokes is much more likely than a nonsmoker to marry a person who smokes at the time of marriage, and the same is true for people who drink alcohol immoderately.
- Among people who marry as young adults, most of those who give up an unhealthy habit after marriage do not resume the habit later in life.
- Among people who as young adults neither drink alcohol immoderately nor smoke, those who never marry live as long as those who marry.
无因无果是不是正确的 ? A否到B否 能不能 推A到B
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