该病人的处理首要的是A．用抗生素 B．等局部有波动感时切开引流 C．及时切开减压 D

生态系统内生物富集常伴随            发生。

．如图所示，19世纪初的英国，报时自鸣钟（闹钟）从富贵人家的装饰品变成市民的日常生活用品，导致这一变化的根本原因是

A．英国市民生活变得富有

B．工厂制的广泛推行

C．制造钟表的成本更低

D．市民生活观念的变化

London, Reuters--What could annoy teenagers enough to make them stop hanging out with friends and go home？

No, it's not a visit from their mothers, and not a threat to take away their cellphones or pocket money.

It's high-frequency noise. The UK police recently agreed to use a device (装置) called the Sonic Teenager Deterrent. It sends out a sound that makes teenagers become so impatient and angry that they have to cover their ears tightly and walk away.

The sound is at extreme high-pitch that can be heard by those under 20. The body's natural ability to detect some wave bands decreases almost entirely after 20, so few adults can hear the sounds. The black-box device, nicknamed the Mosquito because of its sound, can be fixed to the outside walls of shops, offices and homes. It sounds to youngsters like a crazy insect or a badly played violin. But it causes no physical damage.

A number of police forces and councils have given permission to use the system and want to install (安装) it at trouble spots.

Staffordshire Police Inspector Amanda Davies, who has given the device to shopkeepers in the Moorlands area, said," It is controlled by the shopkeepers--if they can see through their window that there is a problem, they turn the device on for a while until the group has run away."

小题1:The device can be used to _______.

A．threaten teenagers in public

B．drive away trouble-makers under 20

C．help mothers control their teenage children

D．help the police control shopkeepers小题2:From the passage we can know that _______.

A．young people often suffer from pains in ears

B．shopkeepers are troubled by noisy insects

C．high-frequency noise is beyond the listening ability of people over 20

D．the police invented a new device to deal with teenagers小题3:The purpose of the writer to write the passage is ______.

A．to advertise a new hi-tech device

B．to tell the reader a piece of news

C．to sell the device to shopkeepers

D．to inform the public as the spokesman of the police小题4:Who will welcome the device most?

A．Shopkeepers.

B．The police.

C．Young people.

D．The producer.

如图所示为材料相同的一根由粗、细两部分组成的木杆，粗杆直径是细杆直径的两倍，粗杆部分长为1cm，木杆放在水中可以竖直漂浮，粗端在下，用它可制成一支密度计．将它放在水中，液面到木杆最下端的距离为13cm；再把它放在盐水中，液面到木杆最下端的距离为9cm，则盐水的密度是多少？（保留两位有效数字）

某城市汽车生产工人的劳动力市场当前处于均衡状态。汽车生产工人的市场工资率为25元/小时，但由于该市最近增加了两家新的汽车生产厂，导致当地对汽车生产工人的劳动力需求出现了大规模增长，由于劳动力供给短期内无法快速增加，因此，该市很可能会出现的情况是（）。

A.汽车生产企业要想获得足够的劳动力，就必须支付25元/小时以上的工资

B.汽车生产企业只要支付25元/小时的工资就能够满足自己的劳动力需求

C.汽车生产工人劳动力市场的均衡就业量会上升

D.汽车生产工人劳动力市场的均衡工资水平会大幅度下降

E.汽车生产工人劳动力市场的均衡工资水平会上升