河边有9只青蛙,跳进河里4只,还剩几只青蛙?,{4D+^/n-F:{.Z+]'K7Z;j1z
算式:提示+y7o*`2N4y,{4D+^/n-F:{.Z+]'K7Z;j1z
答:还剩,O(l:M4}1R/s9G只青蛙。,{4D+^/n-F:{.Z+]'K7Z;j1z