请选择ABCD,C;l-{4N1T1W/q3rThe books are _____ the bookshelf..x2l3K+O1e.[
A. in.x2l3K+O1e.[
B. on.x2l3K+O1e.[
C. over.x2l3K+O1e.[
D. under.x2l3K+O1e.[