單項(xiàng)選擇題
A.5 B.10 C.15 D.20
A.0.2 B.0.3 C.0.4 D.0.5
A.0.005mm∕1000mm B.0.005mm∕2000mm C.0.005mm∕3000mm D.以上都不對(duì)
A.△h=nl∕i B.△h=nli C.△h=ni∕l D.以上都不對(duì)
A.140 B.150 C.160 D.170
A.40 B.50 C.60 D.70
A.0.6 B.0.7 C.0.8 D.0.9
A.2 B.3 C.4 D.5