People in different countries have different ways of doing things. Something that is polite in one country may be quite impolite in another. In Britain, you mustn't lift (举起) your bowl to your mouth when you are having some soup. But it's different in China. And in Japan you even needn't worry about making a noise when you have it. It shows that you are enjoying it. Making a noise is considered as (被认为) bad manners (举止，礼仪) in Britain. If you are a visitor in Mongolia, what manners do they wish you to have? They wish you to give a loud “burp”(打嗝) after you finish eating. Burping shows that you like the food.
    In Britain, you should try not to put your hands on the table when you’re having a meal. In Mexico, however, they hope you keep the hands on the table during a meal. But Arabians consider you must be very careful with your hands. You mustn't eat with your left hand. Arabians consider it very bad manners eating with left hands. So, what should you do if you are on a visit in another country? Well, you can ask the local people to help you or just watch carefully and follow them if you are on a visit in another country.

若是在26颗珍珠中有1颗是假的，至少要称几次才能找到假珍珠呢?请说说你的想法。