川普政府進一步限製合法移民：所有綠卡申請者都得回國通過領事申請

https://www.nbcnews.com/news/us-news/visa-holders-green-cards-return-home-country-trump-rcna346546

Non-immigrant visa holders must return to home countries to apply for green cards, Trump administration says

In a typical year, 1 million people apply for green cards and half of those apply from within the U.S. to change their status while they are living here, a former USCIS official said.