________ (fail) several times, they need some encouragement.
Having failed
暂无解析
Comrade Li ________ be in Beijing because I saw him in town only a few minutes ago.
Howlong________they________(dig)theditch?
________(fail)severaltimes,theyneedsomeencouragement.
You________gonow.It’sgettinglate.
Onlywhenyouhaveobtainedsufficientdata________cometoasoundconclusion.