补全对话（共5小题，每小题1分，满分5分）
A; Hi. You look excited. ___56______?
B: It is said that a singing contest will be held in our school soon. And I think it a good chance to exercise my singing talents.
A: ___57___?
B: A MP3 player will be given as a reward to the first prize winner.
A: Are you going to take part in it?
B: Sure. __58_____
A: Really? But I don’t think you’ve practiced enough.l
B: I’m going to. I bet I can get the first prize.
A: __59_____. I think you need to have a music teacher to help you.
B: I don’t think it necessary.____60_____
A．By the way, are they giving prizes?
B．People say I have a good voice.
C．I don’t know what others say about it.
D．You can do a lot better next time.E.It’ll turn out fine if I practise a lot.
F.What’s happening
G.Don’t be so sure.
，现将它倒置使原底面平行于水平桌面，此时水面的高度与h的比值为（）。