那只猫是我们见过最狡猾的，总能偷到鱼而不被发现。

That cat is the ___sneakiest we've ever seen, always stealing fish without getting caught.

小偷以最隐蔽的方式溜进了房子，没人注意到他。

The thief entered the house in the ___sneakiest way, unnoticed by anyone.