How well do u know Justin Bieber's songs?

Finish Justin Bieber's lyrics.............

1 How Many ________ you let hit the floor. (finish the lyrics)
2 We're big enough to stand in the _______ line.
3 Fool me, fool me oh how you ___me
4 So we fight (so we fight), through the ____ (through the ___)
5 When i met you girl my heart went ____ _____
6 Girl i promise i'll be ______