A.焊點(diǎn)牢固 B.填寫履歷 C.調(diào)整指標(biāo) D.接插件接插牢固
A.1960Hz B.1550Hz C.1520Hz D.1337Hz
A.小于1.5 B.不大于1.5 C.小于2.0 D.不大于2.0