sure怎么读,sure什么意思

i'm not sure wh
sure. how many plates? five. ok! here you are.
滑铁卢大学教授带课进驻b站当up主:be sure to 素质三
make sure和be sure 有什么区别?
be sure to后面是加名词还是动词啊 这个to是介词还是不定式?