美國簽證.20分

I'm not sure whether you are a boy or a girl. If you are a girl and not married, traveling visa to the States will be rather difficult. Not even travelling, even for trade shows or business trip, not easy as well.

It depends on how long ahead of the school starting date you want to be in the States, I believe that you might be able to apply for an student visa to arrive at the States in August. However, the application of course must be supported by your enrolling permit officially issued by the school you are going to attend.

Don't risk to apply for a separate travel visa. Once you are rejected, I'm sure that there are some negative effects on your application of the student visa.

USA is not a friendly country - I mean the Government.

Hope it helps.

申請旅遊簽証的理由充足.

Perhaps you want to prepare some letter/email exchange to help explain your situation, and then apply your B1/B2 visa together with your F1 visa.