有人邀请你，应该准时到达或在比约定时间晚五分钟或十分钟内到达。

You should arrive at the time you were invited for, or within five or ten minutes after that time.

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要约定时间，否则，美国人有时会用一些一般性的邀请，像“找个时间聚聚吧”，但通常这只是表示友善的方法，而非真正的邀请。

Try to set a specific time. Americans sometimes make general invitations like " Let's get together sometime. " Often this is just a way to be friendly. It is not always a real invitation.

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