—Too much homework has made me tired these days, Mr. Zhang. —That’s true. But a small tree won’t grow into a big tree it experiences lots of winds and rains.
-- Mum, must I stay there the whole day?
-- No, you ______ . You ______ come back after lunch, if you like.
A. mustn't; can
B. needn't; must
C. needn't; may