A.5mm B.25mm C.2.5mm D.10mm
A.1.8V B.1.5V C.1.2V D.1.9V
A.重物的重量 B.最經(jīng)濟(jì) C.對(duì)應(yīng)使用狀態(tài)安全、經(jīng)濟(jì) D.最安全