A.1.2~1.5 B.1.0~1.2 C.0.8~1.0 D.1.5~1.8
A.0.5;0.1 B.0.5;0.2 C.0.6;0.3 D.0.6;0.2
A.同時工作的個數(shù) B.三個 C.兩個 D.四個