It's a used book.

这是一本旧书。

There are also lots of used book shops online.

网上也有不少二手书书店。

Take some of your newer books to a used book shop for some moola!

把你一些比较新的书拿去旧书店卖钱！

The used book market takes a huge chunk out of my annual royalties.

我每年的著作版税中有很大一部分来源于往年的图书市场。

In my previous career as a librarian, I used book reviews to make purchasing decisions.

我以前做图书馆馆长的时候，一般根据书评来作采购决定。