A.
B.
C.2
D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]设,且,则是( )。A.B.C.2D.
[单选题]A.1001111B.0110000C.10110111D.10001001
[单选题]A.平衡力系B.一合力C.一合力偶D.一合力与一合力偶
[单选题]A.-1B.7C.-7D.1
[单选题]A.向右平移B.静止不动C.向外扩张D.向中心收缩