Hi, Li Ming, I'm glad that you are coming to San Francisco next month. But I think there is still something I should let you and your friends know before you leave. First, bring a warm jacket and sweater so that you're prepared for changes in the temperature. Even in the summer months of July and August, it gets cold. Second, many of the phone boxes at San Francisco airport and in the center of the city only accept prepaid(预先付款的) calling cards. So a prepaid phone card is needed. I suggest you buy one at the airport. Third, it's not easy to find a hotel room when you arrive. Hotels fill up quickly in San Francisco all year, especially in summer. You'd better book your room before you come. One more thing. San Francisco is a great walking city—but there are hills! Bring a comfortable pair of walking shoes if you're planning to go around on foot. Lastly, there are many wonderful cultural activities in San Francisco year round. Use the Internet to get the latest information about the activities all the time of your visit. Wish you a pleasant trip. | 
