When in Rome, do as the Romans do．If you remember this, you will not go very wrong．For example, a visitor in a Chinese family usually doesn't finish 1 up．He usually leaves a little to show that he has had enough．． 2 in England a visitor always drinks up to show that he likes it．
In some Asian countries, standing very close to a person that you are talking with is quite common．However, if you do so in Europe, some people 3 uncomfortable．
In China, if someone says 4 about you, it is polite to answer “No, not at all”．
In America, they may answer “Thank you! ” 5 a big smile．This may not be common in China, but is a good manner in America．
In Korea, it is polite 6 something to an older person with both hands．In Italy, you don't make the OK sign with your 7 ．In Thailand, you don't touch a child on the head．In England, it is not polite to ask people“ 8 money do you make? ”and Americans don't mind this so much．But in both England and America, it is 9 to ask people how old they are．
In a word, it is very helpful and useful to know something about cultures and customs 10 different countries．