回复：关于Advance Parole的问题。很困惑。

1. most people have H1 status and have no H1 visa. They are different. You can use H1 status to legally stay and work in US, but you have to use visa to enter US. Many people use AP to enter US, just want to avoid apply H1 visa.
2. AP is not visa. you can use it to enter US, but you still have no H1 visa.
3. If you have effective H1 visa, you needn't apply visa again. If you only have H1 status and have no AP, you have to apply visa to return US