There's no simple solution to this problem.
这个问题没有简单的解决办法。
It should have been a simple matter to check.
检查核对本来应该是件简单的事情。
I need a simple yes or no to my questions.
我的问题只需要简单地回答是或不是。
It wasn't quite as simple as I thought it would be.
这事不完全像我想的`那么简单。
The principle behind it is very simple.
其中的原理十分简单。