1．The little boy got punished ________ what he had done.
A．because B．because of C．since D．as
2．We’re looking forward to the holidays when we’ll be travelling ________ camels ________ the Sahara Desert.
A．by；across B．by；through C．on；over D．on；through
3．Follow your doctor’s advice, ________ your cough will get worse.
A．or B．and C．then D．so
