精选优质文档-倾情为你奉上30Suppose(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 dont 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 find my way with 8_ trouble at all ”. Working in math is somewhat（有点儿） like tr
