--These books ____ in the library for along time .--I think

--These books ____ in the library for along time .--I think they are too old to be read .
A.have kept B.had kept C.have been kept D.were kept
顺便也告诉我第一句话是什么时态啊

C
主语是物,要用被动语态,排除A与B,根据FOR A LONG TIME 可知是现在完成时的被动语态,再排除D
加油!不明白再问!如果帮到你,请采纳,谢谢!
再问： 为什么是被动语态就要排除A和B啊，我才学，麻烦讲清，谢谢
再答： 被动语态的基本结构是：助动词be +动词的过去分词。 而A与B是完成时态。