正反馈
参考答案:
反馈的结果是使原有效应得以加强,称为正反馈。
--______ interesting the storybook is!
--Yes. I have read it twice.
A.What
B.What an
C.How
D.How an
感染性发热在发热病因中占()
A.30%~40%
B.40%~50%
C.50%~60%
D.60%~70%
E.70%~80%