表示人的性格特征如勇敢,大胆,聪明,善良,残忍,机灵等等词用于该句型。如果不是这些词句型中的of 就要用for. IT is clever of Tom to refuse the task. IT is bold of them to attend the big gathering. 别的词不表示人的性格特征的词 换 for it is necessary fir us to kearn a foreign language. it is not easy for you to do the job.