试题与答案

关于安全阀的维护使用,()是正确的。A、经常保持清洁,防止阀体弹簧等被油垢污物所粘滞

题型:多项选择题

题目:

关于安全阀的维护使用,()是正确的。

A、经常保持清洁,防止阀体弹簧等被油垢污物所粘滞或锈蚀

B、经常检查安全阀铅封是否完好

C、认真检查安全阀是否有泄露及温度过低时有无冻结的可能

D、安全阀必须实行定期校验制度,一般每三年校验一次

答案:

参考答案:A, B, C

试题推荐
题型:计算题

定值电阻R1、R2和滑动变阻器R3接入如图电路中,电源电压不变。当开关S1闭合,S2断开,R3滑片P位于b端时,电压表V1和V2的示数之比U1:U2=1:2,电流表的示数I1=1A;当开关S1和S2都断开,R3滑片P位于a端时,电压表V1和V2的示数之比U1/:U2/=4:3;已知R1=4Ω,求:(1)滑动变阻器的最大阻值;(2)电源电压;(3)请你通过控制开关S1、S2的断开和移动滑动变阻器的滑片P的位置,使电路中的电流最小,并求出此时电流表A和电压表V1的示数。

查看答案
题型:改错题

短文改错。

    I often quarrel about my mother over whether I can watch TV after school. She holds view that senior one

students have to make fully use of every minute to work hard at their lessons. It seems to me that once I am

allowed to do that. I will unable to control myself and forget all about my study. She also thinks it is bad for

my eye. But I really can not accept her ideas. In my opinion, watch TV can set my mind at rest after a day's

a hard works. Besides, it is important for us to know what had happened at home and at abroad. Thus, we

shouldn't be forbidden to watch TV.

_________________________________________________________________________________________

查看答案
微信公众账号搜索答案