Parents advised me to communicate with my head teacher about the problem ________.
居民楼道中照明灯泡正常工作时的电压是____伏，它与控制其亮暗的“声控开关”是____联连接的．家庭电路中的电能表，其示数单位是____．
----- How long can I ______ the book? ------ Two weeks.
