________What's ten plus ten?
________And one more?
________It's twenty.
________It's twenty-one.
________Right.
Be quiet
It is a rainy Day. Bill and Amy are at home. They are making a cake for their parents. Dad is writing a letter (信).
Mum is working. "There is big noise. Dad and Mum can't work." They say, "Please be quiet. Please go to your room." Now Bill and Amy are in their room. Oh, Bill is playing the violin. Amy is playing the flute. The noise is bigger (更大了).
Their parents can't work. So they say, "Go and make a cake instead."
What are Bill, Amy and their parents doing?