I don't know how Google determines my location; it automatically switches to use
google.com.hk are inaccessible to me in China, so I want to ensure I always use
google.com as the default search site.
I've set the Google language to English, but it doesn't seem to work.
I've also added a custom search rule in Chrome:
http://www.google.com/?q=%s as default - however, this will open the google.com starting page whose search input box is filled with the keywords, but is waiting to be clicked to show the search result.