题目内容：
If you are going to a restaurant for dinner, it is usually a good idea to telephone for a reservation. Cities are crowded and good restaurants will not hold reservations for more than a short time. If you cannot get into a restaurant because you have not reserved ahead, don't be angry．This frequently happens to Americans and visitors alike. Restaurants can only serve a certain number of people atone time，and if they are already filled, they must turn away any additional people who want to dine there. Frequently, a table will be available if you are willing to wait 20 or 30 minutes for it.
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