根据栏中的问句,在栏中选出正确答语。
①How old are you? ____ A. Thank you.
②Happy birthday! ____ B. One cake.
③How many cakes? ____ C. I'm fine, thanks.
④How are you? ____ D. I'm nine.
比一比,谁先过河。
____ (按从左到右的顺序依次填写)