A: I have a little problem with room 507.
B: Problems are what we're here for, sir. Please tell me your problem.
A: This room is filthy with cockroaches.
B: Were you wearing your glasses when you noticed them, sir?
A: I've already seen nine of them and, as they say, eight is enough!
B: Sir, sometimes a fast elevator ride makes our guests see spots.
A: You are not in a position to question my vision or my statement!
B: I'm very sorry, sir. Will you please hold while I transfer you to my supervisor?
n. 电梯,飞机升降舵,斗式皮带输送机