facebook posts from social plugin lack "share"

When we broadcast a new post using the Social plugin, it appears normally on Twitter, but on Facebook it has only two options for users who read it: “Like” and “Comment”. How can I enable the “Share” option in our posts to Facebook, so that the fb message gets proper circulation?

http://ww.wp.xz.cn/extend/plugins/social/

http://ww.wp.xz.cn/extend/themes/social/