半导体发光二极管和半导体激光器在结构上的根本区别是______。_爱下问搜题

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问题填空题

半导体发光二极管和半导体激光器在结构上的根本区别是______。

答案

参考答案：发光二极管没有光学谐振腔

单项选择题 A1型题

慢性肾衰竭时发生肾性贫血的主要原因是（）

A.EPO分泌减少

B.血尿丧失过多

C.叶酸与VitB缺乏

D.铁利用障碍

E.水钠潴留，血液稀释

问答题

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