If there _____no buying and selling of a nimals, there___ no killing in nature.
The boy ___________ go to bed _________ his mother came back.
—You can’t smoke here . Look at the sign.—Sorry, I __________ it.
—Can you help me with my homework , David ?—______________
Jim writes __________ than ________ girl in his class.
____________ I will have a chance to visit Beijing this summer holiday. I’m so excited.