zài / zhí / wù / xué / kè / shàng / wǒ / men / xué / xí / le / mù / lán / gāng / de / zhǔ / yào / tè / zhēng在植物学课上,我们学习了木兰纲的主要特征。In botany class, we studied the main characteristics of Magnoliopsidae.