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问题 填空题

促使液体气化的两种方式：一______，二______．冰块在熔化过程中，不断吸收热量，温度______；水在沸腾过程中，不断吸收热量，温度______（选填“升高”、“不变”、“降低”或“可能升高”）．

答案

（1）液化的方法有：降低温度和压缩体积；

（2）冰属于晶体，晶体熔化时吸收热量，温度保持不变．

（3）水在沸腾时，吸收热量，但温度不变．

故答案为：降低温度；压缩体积；不变；不变．

多项选择题

我国的职工福利制度是在供给制和传统的计划经济体制下形成和发展起来的，其基本特征是：______。

A．业有充分自主权

B．企业办社会、福利项目多，形式单一

C．实行纯粹福利分配

D．福利项目灵活多样
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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.

18（）

A.in

B.to

C.since

D.for
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