用括号内所给动词的正确形式完成短文。
How to Observe the United States
What is the best way to observe the United States? The best way 1 (depend) on how much you want to spend, what part of the country you want 2 (visit), what you want to see along the way, and how much time you 3 (have). Sometimes a combination(联合) 4 (be) the best. 5 (fly)is the fastest and possibly the least expensive way to see America. If you 6 (have)a round trip ticket to the United States, many airline companies have special tickets that let you 7 (fly) at a big discount(折扣价). Although air travel is the fastest, it doesn't allow you 8 (see) very much except clouds when you are traveling. If you want'to see the country from the ground, you should consider 9 (take)a bus. For short trips around a city or to a national park, a rental car 10 (be)a good idea,
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