yán / jiū / rén / yuán / zhèng / zài / xún / zhǎo / gèng / huán / bǎo / de / fāng / fǎ / lái / tí / qǔ / mù / zhì / sù研究人员正在寻找更环保的方法来提取木质素。Researchers are looking for more environmentally friendly ways to extract lignin.