根据以下内容回答题：
People from different cultures sometimes do things that make each other uncomfortable，sometimes without realizing it．Most Americans（1）out of the country and have very little experience with foreigners．But they are usually spontaneous（心血来潮的），friendly and open，and enjoy（2）new people，having guests and bringing people together formally or in-formally．They tend to use first names（3）most situations and speak freely about them-selves．So if your American hosts do something that（4）you uncomfortable，try to let them know how you feel．Most people will appreciate your honesty and try（5）you uncomfortable again．And you’11 all learn something about another culture!Many travelers find（6）easier to meet people in the America than in other countries．They may just come up and introduce themselves or even invite you over（7）they really know you．Sometimes Americans are said to be superficially friendly．Perhaps it seems to be so，but they are probably just（8）a good time．Just like anywhere else，it takes time to become real friends（9）people in the America． If and when you stay with American friends，they will probably（10）introducing you totheir friends and family，and if they seem proud to know you，it"s probably because they are，relax and enjoy it!
1.

A. have never been
B. have been never
C. has never been
D. has been never