簽證上沒此條件，大多數人也必須申請豁免

隻要你的專業在此List上，對大多數國家的人，就需申請豁免。
Exchange Visitor Skills List
http://exchanges.state.gov/education/jexchanges/participation/waivers.htm

An advisory opinion is a request for a statement from the Waiver Review Division as to whether an exchange visitor is subject to Section 212(e) of the Immigration and Nationality Act, as amended.