Sarah and Lily are sisters. Sarah is fifteen and Lily is eight. This summer their parents go to visit their friends in another city. So now only Sarah and Lily are at home. (来源：http://www.EnglishCN.com)
One day when Sarah was cooking in the kitchen, Lily played in the hall. Suddenly Sarah heard something heavy falling to the floor with a big bang. She hurried to the hall. The whole bookcase just fell down, with books scattering all around.
“Oh, no! Who give you the green light to touch that!” Sarah shouted!
“Green light? I don’t touch it with green light. I touch it with my hand!” Lily said seriously.
“Don’t blow smoke!”
“I don’t blow smoke. But you do. See the kitchen.” Lily said quite earnestly.
The kitchen was smoking!
“My pancakes! I would go bananas!” Sarah cried.
Give somebody green light: give somebody permission to do something
Blow smoke: to speak idly, misleadingly, or boastfully
Go bananas: acting crazily or silly