Answer :
"1.Word choice is the most important tool a writer has available" is an opinion since other writers may work better under a different philosophy. "2.Thoreau and Emerson were friends" is a fact although friendship can be interpreted in different ways. "3.Stage directions are critical to a play's production" is a fact because no play can go well without such directions. "4.Thoreau was an influential American" if a fact because he was famous and therefore influential is some way. "5.The Night Thoreau Spent in Jail is an important play" is an opinion because it is a work of creativity.
