四则混合运算是什么简介：Zhao Huai's cheeks were red and his eyes were firm: There is Xuanwu Lake in Ruishan, fifty miles away from the drought area. If the lake water can be used for irrigation, the drought can be easily solved.
Zhao Huai's cheeks were red and his eyes were firm: There is Xuanwu Lake in Ruishan, fifty miles away from the drought area. If the lake water can be used for irrigation, the drought can be easily solved.
