1 . 阅读下面材料，在空白处填入适当的内容（1 个单词）或括号内单词的正确形式。
Booking clerk: Hello, can I help you ?
Customer : Yes, you know, I’d like to fly to Berlin, Germany,    1    the 13th of this month.
Booking clerk : Well, a moment please. I’ll check the    2    (flight). And What time will you come    3    ?
Customer: Let me see. I will attend a book fair    4    (hold) in Berlin, and the next two days a conference about education. Well, I haven’t decided when I’m going to return. Oh, I hope I will have the     5    (cheap) flight. By the way, how much does it cost to go there ?
Booking clerk: Oh, it’s only $870. This is the cheapest.
Customer : It’s fine. Would you like to tell me    6    the flight leaves and arrives?
Booking clerk: No problem. That’s Flight BA975. It    7    (leave) Los Angeles at 11:00 in the morning, and arrives in Boston at 2:35 in the afternoon. Then, you’ll have to change     8    Flight 301 at 4:10, and arrive in Berlin at 7:14 a.m. the next day.
Customer: I think I’ll take    9    . One more thing, I prefer to have a seat in the front and by the window, because I suffer from    10    (airsick) sometimes.