—Look!He's running so fast!—Hard to ________ his legs were once broken.
Only in this way ______ learn English well.
With so much homework to do,David told his sister_____so much noise.
They talked for about an hour of things and persons __________ they remembered in the school.
It was because of his kind nature _______I fell in love with Peter.
They aren’t a good team, but they refuse to _____ and accept the defeat.