guān / chá / zhǒng / zi / de / jié / gòu / shí / wǒ / men / fā / xiàn / dān / zǐ / yè / zhí / wù / tōng / cháng / zhǐ / yǒu / yī / piàn / zǐ / yè观察种子的结构时,我们发现单子叶植物通常只有一片子叶。When observing seed structures, we found that monocot plants usually have only one cotyledon.