,选出下列可以肯定使F=0的取值是( )。[2009年真题]A.ABC=011
B.BC=11
C.CD=10
D.BCD=111
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]已知,,,若,,共面,则等于( )。A.1或2B.-1或2C.-1或-2D.1或-2
[单选题]曲线在处的曲率是()。A.1B.2C.D.