单选题 .  People from different cultures sometimes do things that make each other uncomfortable, sometimes without realizing it. Most Americans     21    out of the country and have very     22    experience with foreigners. But they are usually spontaneous (朴实的), friendly and open, and enjoy     23    new people, having guests and bringing people together formally or informally. They tend to use first names     24    most situations and speak freely     25    themselves. So if your American hosts do something that     26    you uncomfortable, try to let them know     27    you feel. Most people will     28    your honesty and try not to make you uncomfortable again. And you'll     29    something about another culture!
    Many travelers find     30    easier to meet people in the U.S.     31    in other countries. They may just come     32    and introduce themselves or even invite you over     33    they really know you. Sometimes Americans are said to be     34    . Perhaps it seems so, but they are probably just     35    a good time. Just like anywhere else, it     36    time to become real friends     37    people in the U.S.
    If and     38    you stay with American friends, they will probably     39    introducing you to their friends and family, and if they seem proud     40    you, it's probably because they are. Relax and enjoy it!21.