And a smile's ideal width should be no less than halfwidth of the face.另外,嘴唇咧开宽度应达到脸部的一半....

半宽...

halfwidth的音标：halfwidth的英式发音音标为：['hɑ:fwɪtθ]halfwidth的美式发音音标为：['hɑfwɪtθ]...