By the way,

来源: 于 2012-12-28 12:00:09 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

after your child get the 旅行证, he/she needs to use his/her US passport to leave US, use the 旅行证 to enter China; then use the US passport and the 旅行证 to leave China and use the US passport to reenter US.