Zhí / wù / xué / kè / shàng / lǎo / shī / ràng / wǒ / men / guān / chá / qiān / niú / shǔ / de / yè / piàn / hé / huā / xíng植物学课上,老师让我们观察牵牛属的叶片和花形。In botany class, the teacher asked us to observe the leaves and flower shapes of the Pharbitis genus.