看他好像吃了一驚，她感到開心。

　　She had the pleasure of seeing him look surprised.

　　知道有人欣賞我所做的事真讓人開心。

　　It's nice to know that somebody appreciates what I do.

　　孩子們追逐著彼此的影子，玩得很開心。

　　The children were having fun, chasing each other's shadows.

　　我沒有察覺到你那么不開心。

　　I didn't realize you were so unhappy.

　　我沒有察覺到原來他那時(shí)非常不開心。

　　I didn't realize but he was deeply unhappy at that time.