1.How do people in China celebrate birthdays?
throw a party, have birthday gatherings, most people acknowledge their birthday, but they dont actually celebrate it. ( banners, balloons, cakes, candles...)（中国人怎么过生日？有些人开生日聚会birthday gatherings，邀请很多人来庆祝，有些人则不庆祝dont celebrate it）
2. How do you like to celebrate your birthday?
Id like to...get some gifts and have cake and stuff. Or make a long trip to Europe with my girlfriend.
Leap year, once every four years Im able to celebrate my birthday on the 29th Feb. （你想怎么过生日？这个问题太好回答了，可以自由发挥想象力。可以吃蛋糕、开聚会或者到欧洲去旅游。如果有人是闰年的二月二十九日leap year出生的就比较有趣了，生日每四年过一次once every four years 。）
3. What did you do on your last birthday?
went out and got drunk, got showered with gifts, went shopping... went to beijing new oriental school to improve my language ability （同上）
4. Are birthdays more important for children or for adults?
Children. You enjoy growing up as a child, but despise aging as an adult.（小孩过生日可以享受成长的乐趣：enjoy growing up）
For children and for older people its important, for middle aged guys I think its not that important, coz generally they are too busy with work or being a parent....but in retirement its important again because that is a chance they get to see family..... （老人对生日也比较看重，因为他们可以借这个机会见到全家人:get to see family）
5. Do you like to celebrate your birthday with your family or your friends?
Friends, because you can be yourself and do crazy things together. （和朋友们一起庆生要比和父母一起约束少一些，因为可以做自己be yourself，同时还能借机疯狂一下:do crazy things ）
Well...its difficult to choose ONE answer...but honestly, I like celebrating with both of them..