题目

The villagers didn't realize how seriousthe pollution was until all the fish died in the river. →Not until how serious the pollution was. 答案：【1】all the fish died in the river did the villagers realize丁明要步测从学校到少年宫的距离． (1)走50米的距离．第一次走79步，第二次走80步，第三次走81步．丁明走一步的平均长度是多少米？ (2)照这样的步子，他从学校到少年宫走了1100步．学校和少年宫大约相距多少米？