阅读下面短文，掌握其大意，然后从每题所给的四个选项(A、B、C和D)中，选出最佳选项。

　　Knowledge can be usually got in two ways：books and experience．The latter is no less 　　1　　 than the former, and the best means for getting knowledge of the latter is to 　　2　　．Only by travel can one see things outside one's hometown．　　3　　, suppose you have heard and read about New York and have 　　4　　 seen many pictures of it, but you only have a very vague(模糊的)　　5　　 of it unless you have personally visited 　　6　　．

　　Travel can make us know more and 　　7　　 more．Through traveling we can get the 　　8　　 of geography, customs, cultures, and lifestyles of different places and countries．In travel, we can 　　9　　 more friends and know more about the 　　10　　 of other countries and the different ways of 　　11　　．Travel is also one of the best ways of pastime．　　12　　 long period of had and tense(紧张的work, we can 　　13　　 ourselves completely by traveling to enjoy the beautiful places, to visit historic interest, to see different cities of country-side, to meet famous people and to 　　14　　 nice food．

　　Further, travel is good for 　　15　　．One who keeps him indoors all day long is likely to be 　　16　　．By traveling we can get the chance to climb mountains, walk on foot, do more 　　17　　 and breathe more fresh air．

　　Nowadays with all the comforts easy to get and the 　　18　　 speed, many people travel to other places and even other countries just for the sake of 　　19　　 and sightseeing．Traveling is really beneficial(有益的)in many ways．It's well 　　20　　 the time and money．