【概括大意】If you are tired of making vague excuses for another dull summer at home, here is a thought to lift your spirits. You do not need anything so radical as winning a lottery(彩票) to finance a trip to Europe. A student identity card that can be obtained for a few dollars from the Council on International Educational Exchange entitles(给予、授权) you to discount tickets (打折机票) on certain charter flights to London and Paris, as well as reduced admission to many museums, cinemas, and musical events. Once in Europe, you can stay at approved youth hostels for about two dollars a night. So don’t give up your hopes of becoming an international traveler.The main idea of this paragraph is__________.