The safest way for schools to address teachers is to use "professor". If you know the teacher's last name, you can also call him a professor, but don't call him Mr. Teacher, especially for female teachers, because they may care. Don't call the teacher by his first name unless the teacher tells the students to do so.

Don't mark the book casually.

There are many assignments for studying in the United States, almost every course. Some teachers may tell you the progress and homework of each class at the beginning of this semester, and some teachers may tell you in class. If you know what textbooks to use when choosing a course, you can go to the bookstore first, but you should keep the receipt and ask the clerk if you can return the book, because the teacher may change the textbooks after class, and students may drop out after class if they think it is too simple, too difficult or too boring. At this time, you need to return the book. You can't return the used book, so don't write your name, underline or mark it at first.

Don't call black people "Negro"

Negro means "black" in English (BBS). Especially a black man sold from Africa to the United States as a slave; So don't call black people "Negro" in America, especially when talking to white people. Otherwise, the black man will feel his contempt; When it comes to black people, it is best to use the word "black", and black people will accept this title frankly.

Same sex can't dance together.

Same-sex people can't dance together, which is one of the social etiquette recognized by the United States. Dancing with the same sex, others will definitely cast a reproachful look, or think they are gay. Therefore, even if you can't find a partner of the opposite sex, you must never dance with the same sex.

Don't take off your shoes in front of others

In America, if you take off your shoes or go barefoot in front of others, you will be considered a rude savage. Only in the bedroom, or between men and women in love, can you take off your shoes; If women take off their shoes in front of men, it means "you can do whatever you want"; Men take off their shoes; Will be despised as barefoot natives in the jungle. It is impolite for men and women to pull down their socks and garters in front of others; If your shoelaces are loose, you should go to a place where no one is there to tie them.