.l bought a dress which fits me well yesterday.
l lost a package which contained a birthday present
.l borrowed a book from which is about ancient paintings from the library
Martin chose these trousers which tore when he put them on
因为
它们的第二句话都是描述dress ,package,book,trousers
所以就是暗示你后面的句子是以这些词作为先行词,你这样改也没错,只是不太符合题意