阅读下列材料，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。
You may be in the United States only a short time before you are invited to dinner in an American home.Your hosts may telephone you or ask you 61 person, or they may send you a written ___62__ (invite) in the mail. If you get one, you should telephone your hosts to accept.
A dinner in an American home is most likely to be a meal __63__ (serve) to guests sitting at a table. If the guests __64__(seat) at the table, the hosts may serve the food, or it may be passed so __65__ each person may help himself.
There are some other customs you should know. You should arrive on time. When you get there, your hosts may offer you something to drink, and some light food before dinner. The meal is __66_(usual ) served about half _67_ hour after all the guests arrive.
