A.勞動(dòng)消耗定額 B.機(jī)械消耗定額 C.經(jīng)濟(jì)消耗定額 D.材料消耗定額
A.光纜衰減B.光纜波長(zhǎng)C.回波損耗D.光纜芯數(shù)
A.2m高的機(jī)柜 B.1.8m高的機(jī)柜 C.18英寸機(jī)柜 D.19英寸機(jī)柜