Americans often plan social gatherings on short notice, so don't be surprised if you get invited to someone's home or to see a movie or baseball game without much warning. If the time is convenient   for you, surely accept their invitation. But if you're busy, don't be afraid to _ the invitation, perhaps suggesting a time that would be better. Your host won't be shamed. Invitations are usually sent in person or over the telephone. The main exception  is for some formal occasions, in which case a written invitation will be mailed. You would normally receive a written invitation to a wedding . For a casual dinner invitation, don't arrive more than 5 minutes early, because your host may still be preparing for your visit. Arriving more than 10 minutes late is considered rude if very few people were invited. If many people were invited, it's OK to arrive a little late, even as much as half an hour late. For example, it's OK to arrive late for a party, for a potluck   dinner or for a social gathering inviting a large group of people. If you're invited for dinner, it's proper to bring the host a bottle of wine, a gift basket of fruit, a box of candy  , or a bouquet of flowers. Don't bring roses, as men often give roses to women on a date  . If you wish to thank the host for his or her hospitality  , it's right to call or send a brief   written thank-you note the next day. According to the passage, in American   _  .
if you're invited to a family as a guest, you can stay as long as you please. if you're invited for a party, you must always be on time. if you're invited for dinner, you'd better bring some presents. you must make a call to show your thanks after you get home from the dinner.