GbEng
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.
冬天多数虫子作茧。 Most worms cocoon in winter.
毛毛虫必须经过茧的阶段才能变成蝴蝶。 A caterpillar must pass through the cocoon stage to become a butterfly.
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.