来源：学生作业帮 编辑：作业帮 分类：英语作业 时间：2024/05/14 07:29:34
______into use in April 2000, the hotline was meant for residents reporting water and heating supply break-downs. A. Put B. Putting C. Having put D. Being put
解题思路：
解题过程：
选项B.是现在分词表主动，不合题意，C。是完成时，也不表示被动意思。D是进行时的被动语态，于后面的时间状语不符，所以选A.
最终答案：略
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