题目内容：
Dear Jones, You have asked me for suggestions on how to get along in the United States. It is difficult to giveadvice, but I have found the following "dos" and "don'ts" helpful.
As a21,it isn't easy to find anyone to talk to in a big city. However,here are some sugges-tions. First, get or borrow a dog! Walk him several times a day! Americans love dogs and usuallystop to talk to anyone with a dog. Then, try to eat in a cafeteria. People generally22the same ta-bles and will sometimes talk to you if they see that you are a23. Next,take your dirty24toa laundry( 洗衣店) ! It takes about an hour to wash and dry, and many people wait there. They oftenpass the25talking to the other customers.26ask for information from a woman,if you are a27,and from a man,if you are a woman. It seems to get28results for a reason I can't un-derstand. Learn the29:" Please" ," Thank you", and "You're welcome" before you come anduse them all the time! They usually work like magic(魔术).
There are some things you shouldn't do. Don't30the truth when people ask "How areyou?" They only31the answer to be " Fine". Never ask people their32—especiallywomen! Everyone wants to be young. Don't tell heavy people they are33. Tell them they arelosing weight. Everyone here wants to be34. Don't be late for appointments (约会) ! Whensomeone says six o'clock,be sure to be there by six. Americans respect35and expect everyoneto be "on time".
Above all, don't worry! Just follow my advice and bring a lot of money, you will get along. Ihope I have been of some help to you.
Cordially yours,
Socrates
根据以上内容,回答题.
第21答案是（ ） A．result
B．law
C．beginning
D．rule
参考答案：
答案解析：