bombyxin

例句：

1. 1. The butterfly is a beautiful creature that can fly and dance.
   蝴蝶是一种美丽的生物，可以飞翔和翩翩起舞。
2. 2. The caterpillar of the butterfly is its larval stage, which it spends in its chrysalis.
   蝴蝶的毛虫阶段是它的幼虫期，它在这个茧里度过。
3. 3. The swallowtail butterfly is one of the most colorful species in the world.
   燕尾蝶是世界上最色彩斑斓的物种之一。