蚕丝是一种天然的生物聚合物，由蚕分泌产生。

Silk is a natural ___biopolymer secreted by silkworms.

这种由甘蔗制成的生物聚合物可以完全降解，对环境友好。

This ___biopolymer made from sugarcane is fully biodegradable and eco-friendly.