()缺陷严重时,铸坯在加热炉中推钢时会发生拱钢现象。A.中间裂纹 B.气孔 C.菱形

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问题:

()缺陷严重时,铸坯在加热炉中推钢时会发生拱钢现象。

A.中间裂纹

B.气孔

C.菱形变形

考点:加热工考试加热工初级加热工初级题库
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灵敏度的单位是()。

A、dBr

B、dBmo

C、dBm

D、mW

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南宋时期南方经济迅速发展,超过北方。下面哪一项不是南方经济发展的原因?[ ]

A.南方战乱较少,社会较安定

B.许多中原人南迁,带去先进的技术,增加了劳动人手

C.自然条件优越

D.那时政府的财政收入主要来自南方,特别是东南地区

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经营目标市场主要有以下几种模式()。

A.市场集中化模式

B.产品专业化模式

C.市场专业化模式

D.选择专业化模式

E.市场单一化模式

题型:单项选择题

下列有关心脏功能的叙述,正确的一项是  [ ]

A.两个心房收缩,此时两个心室也收缩

B.两个心室收缩,此时两个心房也收缩

C.两个心房收缩,此时两个心室舒张

D.两个心室、两个心房不可能同时舒张,有可能同时收缩

题型: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.

16()

A.specially

B.particularly

C.mostly

D.actually

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