题目

请在正方形内画一个最大的圆，并想办法找出圆心，标出圆心o、半径r和直径d。 答案：20、About 90 percent of the equipment presented by the administration, as well as the facilities of our own, _______ made good use of in the teaching. A．have               B．has          C．have been               D．has been