图1
①接通开关时,灯P2立即就亮,P1稍晚一会儿亮
②接通开关时,灯P1立即就亮,P2稍晚一会儿亮
③断开开关时,灯P1立即熄灭,P2稍晚一会儿熄灭
④断开开关时,灯P2立即熄灭,P1稍晚一会儿熄灭
A.①③ B.①④ C.②③ D.②④
A