回複：申請兄妹移民其間, 他們可以申請旅遊簽證來美嗎?

For Canadian or western european citizens, it is very common until they file I485 or time for CP. For PRC passport holders, you might need to be rich and powerful so VO will believe that you won't COS/EOS/AOS and will return to China after this trip. It;s all about whether you can prove no immigrant intent (at least for this trip) and it's up to VO.