if you can't keep you promise, you will be comsidered dishonst and it will do you no good when dealing with other people 意思是什么呀
although this seems very strange and foolish, it is indeed an excellent way of finding out the truth .a man who is worrying about something had difficuty in(为什么是in 呀)swallowing anything dry.

如果你不遵守若言，别人就会觉得你不可信。在以后的为人处事中这对你不会有什么好处的。
虽然这看起来有些奇怪和可笑，但这的确是找出事实真相的最佳途径。
心中有所忧虑，自然食不知其味。（吃东西觉得难以下咽）
sb have difficulty in doing sth 固定用法“做某事有困难”