采用滚筒驱动的带式输送机应加设软启动装置，下运的带式输送机应加设软制装置。（）

关于酸蚀症，下列哪项正确（）

A.仅有牙本质感觉过敏症状

B.多见于喜食酸性食物者

C.由于酸雾或酸酐作用于牙而造成

D.无牙体实质缺损

E.可引起楔状缺损

限价委托卖出的实际成交价必须等于或高于限定价格。( )

苯二氮类镇静作用优于吩噻嗪之处（）。

A.有暂时性记忆缺失效应

B.可减少麻醉药用量

C.安全范围较大

D.无锥体外系反应

E.减低代谢

患者王某，7岁，患急性淋巴性白血病，接受治疗3个月，病情没有改善。医生征求其父母的意见，问是否愿意使用一种价格较贵的新药，其父母经过考虑，表示同意。因为从未使用过这种药物，也不知道这种药物的效果如何，所以医生决定谨慎使用，严格监控，结果表明，使用这种药物后的效果不明显。从医学伦理的角度分析，正确的是（）

A.医生使用新药，应该征得王某本人的同意

B.该项治疗属试验性治疗

C.效果不明显，与医师使用药物过于谨慎有关

D.因为使用药物后的效果不明显，所以医师的行为不道德

E.医生使用新药物应该征得主管领导批准

As summer rolls around, lawmakers in Washington are preparing to vote on a jobs bill that would include $1 billion for summer jobs for teens. Much of the urgency for the program stems from the private-sector plunge in summer jobs for teenagers over the past few years. It’s no secret that the recession walloped teens’ jobs as much as it did their parents. But some economists find the clamor for public jobs programs a little ironic, given last year’s midrecession minimum wage increase, which may have reduced teen employment even beyond the recessionary drop.

Before the minimum wage jumped to $ 7.25 an hour last summer, University of California-Irvine economist David Neumark estimated that it would lead to an additional 300 000 job losses for teens and young adults. The 2009 wage increase was set in motion in a better labor market in May 2007, when Congress voted to boost the minimum from $ 5.15 an hour to $ 7.25 an hour over the course of the next two years.

It’s hard to parse the jobs lost because of the recession and those lost because of the minimum wage increase--there’s no direct evaluation of the impact of the wage increase yet--but it’s likely that raising the wage floor contributed to the record-high teen unemployment rates, Neumark says. "Almost everyone accepts that minimum wages decrease employment or likely increase unemployment of the least-skilled," he says. Neumark advocated for delaying last year’s increase.

The unemployment rate for teenagers was 25.4 percent in April, compared with 9.9 percent overall, according to the Bureau of Labor Statistics. Teens generally have higher unemployment rates. In November 2007, the month before the start of the recession, the unemployment rate for the overall population was 4. 7 percent, versus 16. 2 percent for workers aged 16 to 19. Teen employment has been declining for some time. The percentage of teens with jobs has fallen from about 57 percent in 1989 to about 40 percent in 2007 (both dates reflect healthy economies). The reasons are diverse. For one thing, increased school enrollment appears to account for about a third of that decline, according to the Economic Policy Institute. "For teens, there has been a remarkable long-term shift from summer employment to summer enrollment," reports EPI economist Heidi Shierholz.

One of the critical issues for job-seeking teens is the changing face of the competition, which is increasingly skilled. "Not only are they competing with each other for available positions, but they are competing with recent college graduates and job seekers who have two or more years of on-the-job experience and are willing to take almost any position that provides a steady paycheck," says John Challenger of outplacement firm Challenger, Gray & Christmas.

The word "walloped" (Line 3, Paragraph 1) most probably means "（）".

A. decreased

B. affected

C. increased

D. hit