单项选择题
A.-3.0DS/+2.0DC×90 B.+1.0DS/+2.0DC×180 C.-1.0DS/+3.0DC×180 D.+1.0DS/+2.0DC×90
A.+3.0DS/-2.0DC×90 B.-1.0DS/+3.0DC×180 C.+1.0DC×180/+3.0DC×90 D.-3.0DS/+2.0DC×90
A.+3.0DS/+5.0DC×90 B.-2.0DS/+3.0×180 C.+3.0DS/+2.0DC×180 D.+2.0DS/-5.0DC×180