管路的联结为不可拆的是（）。 A.阀兰 B.焊接 C.螺纹 D.承插式连接

The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, (51) this is largely because, unlike animals, we stand upright. This means that our noses are (52) to perceiving those smells which float through the air, missing the majority of smells which stick to surfaces. In fact, (53) , we are extremely sensitive to smells, even if we do not generally realize it. Our noses are capable of (54) human smells when these are diluted to far below one part in one million.

Strangely, some people find that they can smell one type of flower but not another, (55) others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate (56) smell receptors in the nose. These receptors are the cells which sense smells and send (57) to the brain. However, it has been found that even people insensitive to a certain smell at first can suddenly become sensitive to it when (58) to it often enough.

The explanation for insensitivity to smell seems to be that the brain finds it (59) to keep all smell receptors working all the time but can (60) new receptors if necessary.

54().

A.distinguishing 

B.discovering 

C.determining 

D.detecting

某同学设计了如图所示的电路测电源电动势E及电阻R₁和R₂的阻值。实验器材有：待测电源E(不计内阻)，待测电阻R₁，待测电阻R₂，电压表V(量程为3.0V，内阻很大)，电阻箱R(0-99.99Ω)，单刀单掷开关S₁，单刀双掷开关S₂，导线若干。

（1）先测电阻R₁。先闭合S₁，将S₂切换到a，调节电阻箱，读出其示数r和对应的电压表示数U₁，保持电阻箱示数不变，再将S₂切换到b，读出电压表的示数U₂。则电阻R₁的表达式R₁＝_________。

（2）甲同学已经测得电阻R₁＝1.8Ω，继续测电源电动势E和电阻R₂的阻值。该同学的做法是：闭合S₁，将S₂切换到a，多次调节电阻箱，读出多组电阻箱示数R和对应的电压表示数U，由测得的数据，绘出了如图所示的图线，则电源电动势E＝________V，电阻R₂＝__________Ω。

下列措施中，能加快蒸发的实例是（　　）

A．把湿衣服放在通风的地方

B．酒精灯不用时盖上灯帽

C．给盛有水的杯子加盖

D．把蔬菜用保鲜膜包好后放人冰箱

孙某因涉嫌诈骗被A县公安局立案侦查并被依法逮捕，在本案的侦查过程中，又发现孙某又涉嫌抢劫杀人，但此时侦查羁押期限已经届满。请回答下列问题。

孙某被逮捕后，下列哪些人员可以为其申请取保候审( )

A．孙某聘请的律师孟某

B．孙某的妻子于某

C．孙某的朋友赵某

D．孙某自己也可申请

气瓶抽空工艺方法是什么？