be-sure-of-与-be-sure-about-的区别

besureof与besureabout的区别,besureof确信例句：Shelookedoverhershouldertobesureofherfooting.她扭头看了看后面以确认自已是否站稳了.besureabout对.很有把握例句：Youcanbesureabouttheirinterestinit.你可以肯定他们对引很感兴趣.