I am sure of his braveness 这里为什么用of

I am sure of his braveness 这里为什么用of His mother might be at home ,but i am not sure of it .为什么要用m i am sure he will do the work( to )his best of his ability为什 I am quiet sure of it,too. I am sure he will do the work to the best of his ability.麻烦对 I am thinking.He is thinking of his life.这里的thinking和thinkin I am in favor of his suggestion. of that I am sure,这句怎么解释 i am sure in favor of your decision i'm sure of that 从句为什么要省略of I am one of the few people left.这里few前面为什么加the she is ___like one of my old friends ,i am not sure of it A