要为我父母办移民，想请教两个问题：
- Is it faster to file I-130 when they are inside US or when they are still in China?
- If I file for my parents while they are in China, is it true that they won't be able to get visa to enter US until they get AP?
- If I file for them while they are here in US, can they go back to China before they get AP?
先谢谢了！