21.Sam ______ some knowledge of the compute just by watching others working on it.
A.brought up B.looked up C.picked up D.set up
22._______, I prefer to stay up later at night ,but not when I’ll have to drive to work the next day.
A. Personally B.Spiritually C.Thoroughly D..Briefly
23.—Shall we go to Shanghai Science and Technology Museum for an autumn outing ?
----- _______ you gave us !
A. What a good advice B.How good an advice
C..What a piece of good advice D.How a good piece of advice