They since last night. They are about to finish the work.(单选题)
.had cleaned the system.,.
have been cleaning the system.,.
are cleaning the system
出自：2024年国家开放大学答案
提示：
同一【IP】的非会员用户每天可免费获取10次答案
收藏本站【zk.995w.com】，下次访问不迷路
本站试题总数:【10245403】个 (题库试题定时更新)
