仔细阅读下列明信片及 Mike，Mary，Linda 的陈述信息，给这些名信片匹配对应的收信人并将A、B、C、D填在相应的位置上。选项中有一项为多余选项。
| Postcards Dear A Thank you for your postcard. Now my family are enjoying the sun on the beach. See you in Sanya soon! Yours, Li Mei | Dear B Lijiang is a good place to visit. Now I am drinking in a pub (小馆)with some friends. We are enjoying the drink. Yours, Jenny |
| Dear C Haven't got your postcard for a long time. I'm in Shanghai. It's a beautiful city. Where are you? Please tell me about it. Best wishes! | Dear D Well, here we are on the Great Wall! It's good place. We are having a good time. We are going back in a week. See you soon! Yours, Kate |
| 21 | Mike | I’m in London now. My friend is in Shanghai. I’m happy to get his postcard. |
| 22 | Mary | I’m in New York now. My friend is standing on the Great Wall. She is going back in a week. |
| 23 | Linda | I’m in Canada now. My friend is visiting Sanya with her family. She hopes to see me there. |
答案解析：
21. Mike的陈述提到了他在伦敦，而他的朋友在上海，所以对应的是C明信片，因为C明信片中提到了上海。
22. Mary的陈述提到了她的朋友在长城上，所以对应的是D明信片，因为D明信片中提到了长城。
23. Linda的陈述提到了她的朋友在三亚，所以对应的是A明信片，因为A明信片中提到了三亚。
