单项选择题
A.1.2; B.1.5; C.1.8; D.2.0;
A.1.0*0.6; B.1.2*0.6; C.1.4*0.8; D.1.5*0.8;
A.1.6,1.8; B.1.8,2.0; C.2.0,2.2; D.2.2,2.4;