have it in one 有能力（做某事）
A：Harry was elected monitor at the class meeting yesterday.
B：Do you think he has it in him to be a good monitor?
A：He’s a good student as far as his achievement is concerned. But I really can’t tell whether he’ll make a good monitor.
A：昨天哈里在班会上被选为班长。
B：你认为他有能力成为一名好班长吗？
A：就他的成绩来说他是一名好学生。但他是不是能当个好班长，我也说不好。