植树节学校要求每班种15棵树,五年一班已经种了一些,还剩4棵没种完,五年一班已经种了多少棵树?+u+Y5A;c,E
算式:提示-r4h2}(t1w0B5G+u+Y5A;c,E
答:五年一班已经种了-Z.n:R2p8a-s0|-z棵树。+u+Y5A;c,E