A.210
B.240
C.273
D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284
[单选题]20×20-19×19+18×18-17×17+…+2×2-1×1的值是( )。A.210B.240C.273D.284