我怎么把椅背放下来？

　　Could you put your seat up, please?

　　请竖直椅背好吗？

　　Everybody, put your hands up for me!

　　大家把你的手举起来！

　　If you have the experience, please put your (right) hand up?

　　如果有过这个经验，请将手举起来！