I think I had at least a billion tests, including _____ in which they cut out a piece of muscle from my leg and looked at it under a microscope.

He has learned         , no matter what happens and how bad      seems today, life goes on and it will be better tomorrow.

He has done_______to improve his writing.

Being a parent is not always easy, and being the parent of a child with special needs often carries with ___ extra stress.  

No pleasure can equal ______ of having a good sleep after hard work.