-
关于需求收入弹性的类型，下列表述正确的是()。
-
在规定条件下，被冷却的油品尚能流动的最低温度称为（）。
-
负压吸宫术的并发症。（）
-
Today ,as in every other day of the year ,more than 3000 U.S. adlescents will smoke their first cigarette on their way to becoming regular smokers as adults. During their lifetime,it can be expected that of these 3000 about 23 will be murdered,30 will die in traffic accidents, and nearly 750 will be killed by a smoking-related disease. The number of deaths attributed to cigarette smoking outweithts all other factors, whether voluntary or involuntary, as a cause of death. Since the late 1970s, when daily smoking among high school seniors reached 30 precent , smoking rates among youth have declined . While the decline is impressive ,several important issues must be raised. First, in the past several years,smoking rates among youth have declined very little. Second,in the late 1970s ,smoking among male high school seniors exceeded that among female by nearly 10 percent . The statistic is reversing.Third ,several recent studies have indicate high school dropouts have excessively high smoking rates, as much as 75 percent . Finally, thouth significant declines in adolescent smoking have occurred in the past decade,no definite reasons for the decline exist. Within this context,the Naional Cancer Instiute (NCI) began its current effort to determine the most effecive measures to reduce smoking levesl among youth. By "dropout" the author means（）.
-
滴定法测定水中氨氮（非离子氨）时，若水样中含挥发性胺类，则氨氮（非离子氨）的测定结果将（）。
-
主动脉夹层动脉病患者测量血压应（）
-
可编程序控制器简称为()。
-
对调速和制动无特殊要求的一般生产机械，应选用（）。
-
为了让紫山中学的高二学生更好地帮助他人，中学老师组织了“义工学习小组”，教导学生一些助人的专业知识和技能，并且通过带他们去敬老院、孤儿院等福利机构让他们可以更加熟悉社会工作的一些方法。“社会工作小组”是（）。
-
英国历史法学的主要代表是（）