Paper ____ first ____ about two thousand years ago in China by Cai Lun.( )
A.is; inventingB.is; invented
C.has; inventedD.was; invented
Paper ____ first ____ about two thousand years ago in China by Cai Lun.( )
A.is; inventingB.is; invented
C.has; inventedD.was; invented
试题篮
()