I would greatly appreciate it if you didn't ...........  up that old argument again. 

 Who would like to ..............  off the debate?

As far as I was concerned when the accident happened, it was the..............   of the end.

 I won a lot of money by betting on that horse but it was simply a case of .............  luck

He..............off at me again simply because I had forgotten to lock the back door after I came home. 

 I can't ................to understand why anyone would want to be cruel to animals.