1.我拿不准这本书是谁的.
I'm uncertain about whose this book is.
或：I'm not sure about whose book this is.
2.约翰提到了几个法官的名字,他对他们评价不高..
John mentioned some names of the judges,who he didn't think highly of.
或：John mentioned some names of the judges,of whom he didn't think highly.
3..毫无疑问,搜寻那些丢失的文物的工作还会继续下去..
There is no doubt that the workof searching for the lost cultural relics will still go on / continue.