火灾逃生时()。 ["A、大声呼叫 ","B、要用湿毛巾,捂住口鼻,屏住呼吸,且须采取匍匐式前进逃离 ","C、用湿毛巾折叠,捂住口鼻 ","D、有烟雾时,要站直行走"]
手动截止阀的作用有()。 ["切断","调节","导流","分流"]
影响视力的因素包括() ["中央凹视锥细胞直径的大小","视觉中枢的分析能力","眼的折光能力","光源的强弱和物体同背景的对比度","晶状体的弹性"]
占整个电视消耗功率最大的电路是()电路。 ["场扫描","行扫描","电源","伴音"]
每一个C类地址有多少个IP地址能分配给主机使用()? ["256","65532","32766","254"]
流水别墅