1.keep one's mouth shut; keep mum; shut the mouth tightly and not speak
钳口不言收藏指正
2.keep silent; hold one's tongue; keep silence; keep silent and say nothing; seal one's lips and say nothing; keep one's mouth shut and say nothing
缄口不言收藏指正
3.How can one keep his mouth shut and watch a man fall into a snare?
人总是要斗的，总是要钩心斗角的和人争逐的。收藏指正