Mr Smith likes to be exact . One day when he is walking in the street ,a woman comes and asks him, "Excuse me, where's the nearest bookshop?" "The nearest bookshop? You have to cross a bridge and then turn to the right. When you see a post office, turn left. You can see a shop between a bank and a school on your right." "Is it far?" "No, it is not far. You can go there on foot." "Is the bridge long?" "Yes, it's about thirty metres." The woman thanks him and goes towards(, ) the bridge. Suddenly she hears someone running after her."Stop!" Mr Smith shouts."I'm sorry. I just remember the bridge is forty metres long. If you go thirty metres and then turn to the right as I told you, you will fall into  the river." Mr Smith follows the woman to   _   .
go with her together lead  her to the shop himself tell her the shortest way warn  her not to fall into the river