蚕吐丝把自己包裹在茧里，等待变成蛾子。

The silkworm spins a protective ___cocoon around itself while waiting to become a moth.

退休后，他把自己包裹在书籍和音乐的舒适茧房里。

After retirement, he surrounded himself with a comforting ___cocoon of books and music.