气体输送设备有离心风机，鼓风机，（）及真空泵等。
2016年政府工作报告提出，做好“十三五”时期经济社会发展工作，实现全面建成小康社会目标，必须着力把握好三点：（）。 牢牢抓住发展第一要务不放松。 科学推进新型城镇化。 大力推进结构性改革。 加快新旧发展动能接续转换。
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.
According to the author, the deaths among youth are mainly caused by （）. traffic accidents。 smoking-related desease。 murder。 all of these。
口、△、○分别代表三个数字，如果口÷△=○，则下列哪一个结论不正确？（） 口=△×○。 △=口×○。 △=口÷○。 口=○×△。
以下情形属于特别重大旅游事故的是（）。 有1人受重伤。 有1人死亡。 经济损失在100万元人民币以上。 有2人轻伤。
对重大安全事故的处理，应由（）牵头。
