A.变长 B.变短 C.不变
A.液压 B.气动 C.电动 D.人工
A.1.0~1.2 B.1.0~1.5 C.1.2~1.5 D.1.5~2.0
A.60 B.80 C.70
A.20 B.30 C.40 D.50
A.2-1 B.5-1 C.5-2 D.9-2
A.70% B.95% C.88%