if you become rich,you will have a difficult time knowing who your real friends are.
问题描述：
if you become rich,you will have a difficult time knowing who your real friends are.
请问know为什么加ing
然后那个difficult time，不是困难时间吗，在这咋翻译，然后再说出整句翻译,
答
have +a +adj.+time 这个句型后面是加-ing.形式,译文是：如果你变得富有了,你将很难知道谁是你真正的朋友