My friend's birthday ia April 15th.(对画线部分提问) ( )is( ) friend's birthday?

问题描述:

My friend's birthday ia April 15th.(对画线部分提问) ( )is( ) friend's birthday?

when your

My friend's birthday ia April 15th.(对画线部分提问)
(When )is( your) friend's birthday?

when is your friend's birthday?

When is your friend's birthday?