光纤包层位于纤芯的周围,直径为()。A.4μm B.10μm C.50μm D.12 发布时间:2017-02-12 21:38 │ 来源:www.tikuol.com 题型:单项选择题 问题: 光纤包层位于纤芯的周围,直径为()。A.4μmB.10μmC.50μmD.125μm
题型:单项选择题 From where I stand, the key to the test is to practise English every day.A.passing; speakingB.passing; to speakC.pass; speaking D.pass; to speak 查看答案