放棄美國國籍

http://travel.state.gov/law/citizenship/citizenship_776.html
A person wishing to renounce his or her U.S. citizenship must voluntarily and with intent to relinquish U.S. citizenship:
* appear in person before a U.S. consular or diplomatic officer,
* in a foreign country (normally at a U.S. Embassy or Consulate); and
* sign an oath of renunciation

Depending on the work load of the embassy/consulate you applied to, it can be days to weeks for a certificate to be issued that certifies you have lost the citizenship of US.

是否你本人自已？你有否參加入籍考試？考中文或英文？

應該要一段時間