Paper ____ first ____ about two thousand years ago in China by Cai Lun.( )
A.is; inventingB.is; invented
C.has; inventedD.was; invented
Buses stop when the traffic lights turn red.( )
A.canB.mayC.must
room looks very clean.( )
A.Bob and Dave'sB.Bob's and Dave's
C.Bob's and Dave
﹣ dictionary is this?It's very nice.
﹣I think it is Mary's.( )
A.WhoB.WhoseC.Whom
They often have three meals day. They have dinner at 6:30 pm every day.( )
A.a;aB.a;theC.a;不填
All the classmates enjoyed the cake _________I made at the party. It was really delicious( )
A.thatB.whoC.what