根据所给中文意思，完成下列各句。

1．我到达火车站时，火车早已开走了。

   By fhe time I got to the station, the train________ _______ _________．

2．他已经意识到自己出错了。

    He realized that he________  __________ a few mistakes.

3．在聚会结束时他才到场。

    He didn't __________ __________ until the party was over.

4．我等着他出来，但是他从后门走了。

    1 waited for him to __________  __________ ，but he left through the

back door.

5上个星期六晚上，汤姆邀请我去参加他的生口聚会。

    Tom___________me_____________his birthday paity last Saturday

night.

到牧民家做客，主人首先会给宾客敬上一碗奶茶，宾客要怎样做才是最合适的？