Set google.com as you default search engine for firefox

Install always google.com plug-in :

https://addons.mozilla.org/zh-CN/firefox/addon/always-com-googlecom-in-englis/
http://mycroft.mozdev.org/google-search-plugins.html

also reference to this article:
http://www.wikihow.com/Change-Your-Browser%27s-Default-Search-Engine

2B or not 2B ,That's a question.