【单选题】听力原文:M: Oh, will you tell me when I get Hayfield Road, please? W: It's only three stops from here. I tell you when we get there, it's my stop, too. M: Thank you. That is very kind of you. W: Don't men...
【判断题】All the vibrations could be expressed by the superposition of harmonic vibrations. And whether the result of superposition of some harmonic vibrations is a harmonic vibration depends on the superposit...