这首是什么歌啊（歌手和歌名）拜托各位大神

这首是什么歌啊（歌手和歌名）拜托各位大神
You know I can't smile without you I can't smile without you I can't laugh and I can't sing I'm finding it hard to do anything You see I feel sad when you're sad I feel glad when you're glad If you only knew what I'm going through I just can't smile without you You came along just like a song And brighten my day Who double leave that you were part of a dream Now it all seems light years away And now you know I can't smile without you I can't smile without you I can't laugh and I can't sing I'm finding it hard to do anything You see I feel sad when you're sad I feel glad when you're glad If you only knew what I'm going through I just can't smile Now some people say happiness takes so very long to find Well