on a sunny morning, xiao hong from orange town was on her way to her friend"s house in green hill, a small town she had never been to before. at a crossroads, she found the signpost showing the directions had fallen over. she got lost.
how could she find out which way to go? consider two or three different ways of working out the problem.
first of all, xiao hong could ask a passer-by for directions.since it was a sunny day, she could also use the position of the sun to tell the directions. and finally she could also replace the signpost so that it correctly named the direction she had come from. then it would be correct for all the other directions.