“春蚕到死丝方尽,蜡炬成灰泪始干。”家蚕的发育过程中,能吐

 “春蚕到死丝方尽,蜡炬成灰泪始干。家蚕的发育过程中,能吐丝的时期是(  )

A                   B                   C                   D

答案

B 幼虫期未吐丝做茧成蛹。

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