A.
B.
C.
D.
[单选题]A.B.C.D.
[单选题]A.8i+98jB.4i+144jC.8i+144jD.4i+98j
[单选题]A.25cmB.50cmC.250cmD.500cm
[单选题]A.4.2mB.3.3mC.5.0mD.2.0m