Everyone knows _____ is dangerous to play with fire, but _____ is difficult is to prevent children from playing with fire. [ ]

MrBrown is _____ a teacher to us; we look on him as our friend[ ]

I thought the actor was famous, _________ none of myfriends has ever heard of him.

This book us a very interesting story.

He felt curiousthat he asked many questionsabout it.