已知函数f（x）=$\left\{\begin{array}{c}{x}^2+2x,x\le 0\\ f\left(x-1\right)+1,x>0\end{array}\right.$，当x∈0，3时，方程f（x）=x的所有根之和为____ 

放学后你和另外一个同学到河边去玩，不小心你落入水中，这时你（  ）

A. go to see him         

B. have a lot of fun

C. under the tree                    

D. at Christmas

E. a Christmas tree                

F. buy presents

G. a turkey and Christmas puddings

A:What do you do ____?

B: First, we ____ for our family and friends. We need to buy____.We put our presents ____.It looks great.

A:What do you like best at Christmas?

B:I like Father Christmas. We sometimes ____.

A:What do you eat that day?

B:I eat ____ .

A:So you ____at Christmas.