Please excuse me _______ your letter by mistake.
Time is life; therefore, waste your time and waste your life, ______ master your time and master your life.
—The exam was too difficult, wasn’t it? —Yes, I don’t think ______ could pass it.
People in the west make ____ a rule to buy Christmas presents for their relatives and friends.
--- What are you going to do tomorrow?--- I will go _____ with my friends on the lake.
You _____ practise the drums while the baby is sleeping.