—Whose dictionary is this?
—It ________ be Sarah’s. Look! Her name is on it.
must
mustn’t
need
needn’t
Mr. Li makes me ____, because it is bad for my health.
Tom didn’t go hiking with his classmates ____ his illness.
How will you feel when ____?
Do you have difficulty ____ English?
—Why do you ____ very happy this afternoon? —Because we are going to spend the evening at Lily’s house.