下列不属于酶原激活方式调节的酶是（）。 A.胃蛋白酶 B.胰蛋白酶 C.弹性蛋白酶

在机械加工工艺过程中，首先要加工精基准面，这是为了（）。

A.消除工件中的残余变形应力，减少工件变形误差

B.使以后各道工序加工有精确的定位基准

C.避免主要的加工表面产生加工硬化

D.有利于减小以后各工序加工表面的表面粗糙度

脱疽好发于：（）

A.四肢末梢

B.小腿下部

C.骶尾部

D.髋部

E.脊背部

某二级建筑土质边坡高为8m，侧向土压力合力水平分力标准值为200kN/m，挡墙侧压力分布情况是：自0～2m为三角形分布，2～8m为矩形分布，在2m、4.5m、7.0m处分别设置三层锚杆，第二层锚杆的间距为2.0m，采用永久性锚杆挡墙支护，锚杆钢筋抗拉强度设计值为f_y=300N/mm²锚杆倾角为25°，锚杆钢筋与砂浆间连接强度设计值为f_b=2.1MPa，锚固体与土体间黏结强度特征值为35kPa，按《建筑边坡工程技术规范》计算，(对第二层锚杆)。

如外锚段长度取0.5m，自由段长度取5.0m，锚固段长度取9.0m，锚杆总长度为（）。

A. 9.0m

B. 14.0m

C. 14.5m

D. 15m

阅读理解。

     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 (波段) 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 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."

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

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

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

4. Who will welcome the device most?

A. Shopkeepers.

B. The police.

C. Young people.

D. The producer.

患儿男，生后2天，出生体重为2400g。因吸入性肺炎入院，入院时患儿呼吸急促，口唇稍发绀。即置于辐射保暖床上抢救。

该患儿吸氧的流量应选择每分钟为（）

A.1L

B.2L

C.3L

D.4L

E.5L