—She____(visit) her grandparents. She usually____(visit) them on Sundays. She____(visit) them again this Sunday.
北半球陆地大多数地方月平均气温最高值出现在
平行四边形的面积一定,底和高成反比例.
如图,是一条河,C是河边AB外一点:现欲用水管从河边AB,将水引到C处,请在图上画出应该如何铺设水管能让路线最短.并说明理由.