Gb	Eng
蚕茧是由昆虫制造的一种由丝组成的外包层。	A cocoon is a kind of silk covering made by an insect.
这些蚕的吐丝量很大.	The silkworms are producing well.
孩子们撕开蚕茧看看里面有没有蛹。	The children tore the cocoon open to see if there was a pupa.