1.经典句型：Sorry,these books are on reserve.
A: I'd like to check them out.
B: Sorry,these books are on reserve.
A: So I have to read them here.
B: The reading section is over there.
2.经典句型：The magazines,newspapers and periodicals have to be read within library.
A: May I borrow these magazines?
B: Sorry,you can't. The magazines,newspapers and periodicals have to be read within library.
A: I see.
on reserve表示“保留”。These books are on reserve.意思是“这些书要保留在图书馆里，不能外借。”inreserve也有“保留，存留”的意思。