多项选择题 末端试水装置开启后，哪些组件和喷淋泵应动作？ A 水流指示器 B 水力警铃 C 闭式喷头 D 压力开关 E 湿式报警阀

单项选择题 "Wife", which used to refer to any woman, stands for "a married woman" in modern English. This phenomenon is known as ______.A.semantic shiftB.semantic broadeningC.semantic elevationD.semantic narrowing

单项选择题 某办公室有9名男教师、5名女教师，现要选出3个代表，则选的3个代表中至少有1个女教师的概率为