happy的副词形式是什么?

　　I wished her a happy birthday.

　　我祝她生日快乐。

　　You don't look very happy today.

　　你今天好像不太高兴。

　　Happy birthday, sweetheart.

　　生日快乐，亲爱的。

　　She had a happy childhood.

　　她有一个幸福的童年。