完成对话。 玲玲要去英国学习，她向她的网友玛丽了解英国的有关礼仪。 Ling Ling: I'm going to England as an exchange student. Mary: Great! Ling Ling: But I don't know much of the customs and manners in England. ___ 1 __. Mary: Sure. Ling Ling: ___ 2 __. Mary: Well, they think it's important to be on time when you're invited to dinner. __3___ . As it is usually planned to have the meal at the exact hour. Ling Ling: Then how long may I stay there? Mary: __ 4 ___, it seems that you have come only for the meal. An evening dinner invitation usually implies  that ___ 5 __. The hostess often plans some after-dinner entertainment. A. you stay for the whole evening B. Could you help me? C. It's not polite to leave shortly after the meal is over. D. It's impolite to arrive late. E. What rules do they have in England?