One summer evening during a violent thunderstorm1) a mother was tucking her small boy into bed.She was about to turn off the light when he asked with a tremor2) in his voice，“Mommy，will you sleep with me tonight ?”The mother smiled and gave him a reassuring3) hug. “I can' t，dear.” She said.“I have to sleep in Daddy's room.”Along silence was broken at last by his shaky little voice：“The big sissy4).”