I know how you feel, but there's no need to go on and on about it.
我知道你的感受,可是也没必要这样没完没了。
The student is busy studying math.
这个学生忙于研究数学。
The administrative overheads of a business are low to the extent that everyone working in the business can be trusted to behave in a way that best promotes the interests of the firm.