同学们种花，每个人种4棵，3个人一共种了多少棵?3r;q4k*[8d.W1g,W5f(z;u+x4B
算式：提示3A7U0{5}6Q5y3r;q4k*[8d.W1g,W5f(z;u+x4B
3个人一共种了7Q5E1S;d8m/b8}3}+@)\9p;p2G8S棵。3r;q4k*[8d.W1g,W5f(z;u+x4B