问题 单项选择题

在人类的身体中,细菌的数量要远远多于人体的细胞,其中大部分细菌对人是有益的,有助于我们消化食物。但是,肠道内的有益细菌有时会死亡或被清除。阑尾不仅能重启在患病时被删除掉的肠道系统内的有益细菌,而且因其所处的位置正好在正常的食物流以下,作为大肠的死胡同,它贮存了各种各样的细菌。这些都说明阑尾就像一个安全的备份盘。从形状上看,阑尾就像一个蠕虫似的器官。实际上,它是一个细菌加工厂,培养着对人有益的细菌。但是,在疾病流行之时,如霍乱影响到某个地区,阑尾就不可能轻而易举地培养出细菌。 下列关于“备份盘”和“加工厂”的解说,不正确的一项是:

A.阑尾就像一个“备份盘”,是因为它能重启因疾病被删除掉的肠道系统内的有益细菌

B.在疾病流行之时,阑尾不能培养出细菌,所以它并非严格意义上的细菌加工厂

C.形状像蠕虫似的阑尾,能培养对人有益的细菌,就像一个细菌加工厂

D.阑尾贮存了各种各样的细菌,且处在正常的食物流以下,作为“备份盘”,很安全

答案

参考答案:B

解析: B项不正确,原文只说“阑尾就不可能轻而易举地培养出细菌”,而不是“阑尾不能培养出细菌”。

问答题 简答题
单项选择题

Drug use is rising dramatically among the nation’s youth after a decade of decline. From 1993 to 1994, marijuana use among young people (1) from 12 to 17 jumped 50 percent. One in five high school seniors (2) marijuana daily. Monitoring the Future, which (3) student drug use annually, reports that negative attitudes about drugs have declined for the fourth year in a row. (4) young people see great risk in using drugs. Mood-altering pharmaceutical drugs are (5) new popularity among young people. Ritalin, (6) as a diet pill in the 1970s and now used to (7) hyperactive children, has become a (8) drug on college campuses. A central nervous system (9) , Ritalin can cause strokes, hypertension, and seizures. Rohypnol, produced in Europe as a (10) tranquilizer, lowers inhibitions and suppresses short-term memory, which has led to some women being raped by men they are going out with. (11) taken with alcohol, its effects are greatly (12) . Rock singer Kurt Cobain collapsed from an (13) of Rohypnol and champagne a month before he committed (14) in 1994. In Florida and Texas, Rohypnol has become widely abused among teens, who see the drug as a less expensive (15) for marijuana and LSD. Alcohol and tobacco use is increasing among teenagers, (16) younger adolescents. Each year, more than one million teens become regular smokers, (17) they cannot legally purchase tobacco. By 12th grade, one in three students smokes. In 1995, one in five 14-year-olds reported smoking regularly, a 33 percent jump (18) 1991. Drinking among 14-year-olds climbed 50 percent from 1992 to 1994, and all teens reported substantial increases in (19) drinking. In 1995, one in five 10th graders reported having been drunk in the past 30 days. Two-thirds of high school seniors say they know a (20) with a drinking problem.

17()

A. even though

B. as if

C. as long as

D. as soon as