—People ________ wear helmets(头盔)when they ride e-bikes according to the traffic rules.
—Yes. Or they will be punished.
must
can
may
These cakes ________delicious! Can I have ________ one?
Jim with his teacher ______ over there.
—How many ______ are there in your school? —There are twenty-one.
—What _______ animals do you like? —I like koalas.
________ people________ walking along the beach.