On the table she found a piece of paper_ some puzzling secrets codes.
A. which was written
B. that was written
C.on which were written
D.on that was written
On the table she found a piece of paper_ some puzzling secrets codes.
A. which was written
B. that was written
C.on which were written
D.on that was written
C.on which were written
本题考查介词加关系代词结构,介词后面只能使用which或whom,write意思是写,密码是写在纸上的,所以要加上介词on