Which function is NOT served by building a prototype

A．It takes the place of the final syste

B．It assists in gathering software requirement

C．It assists in estimating the cost of the projec

D．It is used as the foundation of the larger project

具有清热解毒、利咽、消肿功效的药物是（）

A.山豆根

B.马勃

C.牛蒡子

D.薄荷

E.射干