however

This is a cheap and simple process. However, there are dangers.

这是个花钱少而又简单的方法，不过有危险。

an extremely unpleasant disease that is, however, easy to treat

一种让人极其难受却容易治疗的病

You should report any incident, however minor it is.

任何事件你都应该汇报，不管它多小。