21.----Could you do me a favour and take these books to my office?
---- Yes._______.
A.for pleasure B.I could C.my pleasure D.with pleasure
22._____ walk is expected to last all day,so bring_____ packed lunch.
A.A;a B.The;X C.The; a D.A;X
23.The place______ the bridge is supported to be built should be _____ the cross river traffic is the heaviest
A.which; where B.at which;which
C.at which;where D.which;in which