Yī / shēng / zài / zhǐ / shàng / huà / le / yí / gè / héng / qiē / miàn / fāng / biàn / dà / jiā / lǐ / jiě / jié / gòu

医生在纸上画了一个横切面，方便大家理解结构。

The doctor drew a cross-section on the paper to help everyone understand the structure.