他是第三种，他好像不明白英语，起了冲突，然后被驱逐了。这种情况也能行吗？
-Do you mean the US Customs officer allowed him to enter US from Mexico and then, deported him from US to China? He may need to check the deportation letter to see what the deportation reason was and how long he needed to wait outside US before he applies for a visa to enter US (e.g., 5 years, 10 years). Normally he should be banned for 5 years, or 10 years because his deportation was not due to a crime. So, it should be OK for him to apply for the visa because he has been out of the United States for more than 10 years..
签证的时候也要说明这些吗？
-Yes, he needs to report it in the visa application form, DS160.
