完型填空。阅读下面短文，掌握其大意，然后从以下题所给的A、B、C、D四个选项中，选出最佳选项。
Suppose(假设) you are going to Boston, and you 1 the city
before. If someone 2 you about the interesting places in the city, you __3 to get some ideas of what you will see. But don’t have a 4__ idea of where these places are or of how to find 5 . However, 6__ someone has a map of the city and 7 you the main roads and buildings, you may say, “Oh, now I see. I can
