單項(xiàng)選擇題
A.2B.3C.4D.5
A.±6B.±5C.±4D.±3
A.3B.5C.8D.10
A.-5,+2B.-2,+5C.-5,+10D.0,-5
A.20B.15C.8D.5
A.50B.40C.30D.20
A.0,-200B.+20,-150C.+30,-100D.+30,-50
A.+50,-20B.+30,-30C.+20,-20D.0,-20
A.50,60B.40,50C.30,50D.20,30
A.4B.3C.2D.1
A.5B.4C.3D.2