. As a volunteer, he often goes to the hospital to ________ the sick.
We should have ______fast food, ________fresh vegetables and take enough exercise.
Why ________ come and play basketball with us?
—Your English is very good. —But my brother learns it much ______than I do.
Funny jokes can always make us _____ when we are sad.
-- ________ your teacher __________ ? -- She is friendly and helpful.