假设你是李华，你的美国笔友Bill最近正在中国一所中学作交换生，但是他对于中美之间身势语的差异感到困惑，因此发邮件向你寻求帮助．请根据以下要点提示给他回一封邮件．
1．在美国，人们尽量避免身体接触（contact），但在中国则不然；
2．在美国，人们注重私人空间（private space），但中国人并不是特别在意；
3．在美国，吐舌头是很粗鲁的行为，但在中国则是尴尬（embarrassment）时的表现．
注意：1．词数100左右（信件的开头及结尾已给出，但不计入总词数）；
2．信件需包括所给要点，但不必逐句翻译；
3．可以适当增加细节，以使行文连贯．附：舌头
Dear Bill，
I'm glad to hear that you are studying in China．But you said you get quite confused sometimes，and want to know some simple Sino-US differences in body language．I think I can explain some to you．

Firstly，Americans will avoid touching．But Chinese people don't mind physical contact-girls will even hold hands．Also，people from America protect their private space，while Chinese pay less attention to it．Last but not least，in the United States，showing your tongue is considered to be rude，while in China，it is usually an expression of embarrassment．
There are many differences in body language between China and the United States，please pay attention and use the correct body language when you are in China．I really would like to help you when you are in need．

Firstly，Americans will avoid touching．But Chinese people don't mind physical contact-girls will even hold hands．Also，people from America protect their private space，while Chinese pay less attention to it．Last but not least，in the United States，showing your tongue is considered to be rude，while in China，it is usually an expression of embarrassment．
There are many differences in body language between China and the United States，please pay attention and use the correct body language when you are in China．I really would like to help you when you are in need．

Best wishes，
Li Hua．