我是加拿大公民，过去一直用TN，进出美国也不需要签证。最近换成了H1B，并准备回中国度假，请问回美国时需要签证吗？
-No. Just show your H1 approval notice, the employment verifcation letter from your employer (may also bring your recent 3 month paycheck stubs in case) and your passport to the CBP officer as yopu did for your TN.
