2.Teenagers' safety has become a big problem which catches everyone's attention nowadays. Students should know the way of saving and protecting themselves any minute.As teenagers,we will be much safer if we________. ①never tell anyone online our real names or addresses ②don't walk alone outside at night ③fight with the stranger who is following us ④don't use earphones when running in the schoolyard or on the street ⑤accept anything to drink or eat that's offered by others in a strange place( ?。?/h2>