... higher, they'll fall harder.A. The higher they rise, the more harder they'll fall. B. They fall harder because they rise high.C. The higher they rise, the harder they'll fall. D. ... can't defend ourselves.D. Vigilance is not the only way to defend ourselves.11. Because the street was crowded with people, I couldn’t drive fast.A.If the street weren’t crowded with people, ... higher, they'll fall the harder.10. The only way to defend ourselves is vigilance (thận trọng).A. We defend ourselves by being vigilance.B. If we want to defend ourselves, vigilance is...