完形填空I'd heard about the benefits of gratitude.What was less

完形填空
I'd heard about the benefits of gratitude.What was less clear was what to do.Hoping for--1--,I called Robert Emmons.He was---2---at the University of California."Be----3---,"he said "and soon you'll know the benefits."He--4----that I should pay a gratitude visit."--5--a person who has made a great difference to your life and whom you're ---6--thanked."
1.A.stories B.tips C.thanks D.examples
2.A.teaching B.traveling C.searching D.studying
3.A.happy B.careful C.interested D.thankful
4.A.suggested B.shouted C.doubted D.lied
5.A.Look at B.Think of C.Cheer up D.Look through
6.A.always B.also C.already D.never