回复：请教各位有经验的：B2来美，持单程机票，入境时会有麻烦吗？谢谢

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.