如果有人问how are you doing 我应该怎么回答比较好

How are you doing?是完整的问法.现在时态可变为How have you been?意思是一样的.
How are you?是省略问法.我们中国人使用最多的问法.
你可以这样回答：
1.i am doing fine
2.i am doing well
3.i am doing great