教室前面有两排树，每排都是9棵，教室前面一共有多少棵树？9i8t(@0t-P0A8u6H(z/l
算式：提示3j6c:M8@4B5D,R;D8k9i8t(@0t-P0A8u6H(z/l
答：教室前面一共有/W/w4N3O+D(}棵树。9i8t(@0t-P0A8u6H(z/l