回複：請教各位有經驗的：B2來美，持單程機票，入境時會有麻煩嗎？謝謝

When my parents visited us the second time, they were questioned and put into a small room for a few hours, just because of their one-way ticket.

Since then, I always bought round-trip tickets for them. I would defintely suggest you do the same, even though most custom officers probably do not care about it.