他采用了有效的方法来解决这个问题。的翻译：He used effective methods to solve this problem. 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

He used an effective method to solve this problem.

He used effective methods to solve this problem.

He used the effective method to solve this problem.

He has introduced effective approaches to the problem.

He used effective methods to solve this problem.