英语习语: grit one's `teeth (a) keep one's jaws tight together 咬紧牙关: (b) (fig 比喻) summon up one's courage and determination 鼓起勇气下定决心:When things get difficult, you just have to grit your teeth and persevere. 遇到困难只需咬紧牙关坚持下去.