13.18Hong Kong has about______ beaches. 19.People can go to most of the beaches by bus and go to some places_______. 20.Never swim when you feel______ or_______. 21.A red flag means it is dangerous for_______ and a blue flag means it is dangerous for______.
14.it,to,you,take,did,the other side of,last night,the river,to,ten minutes,swim(连词成句) Did it take you ten minutes to swim to the other side of the river last night?