kàn / dào / dì / di / yì / běn / zhèng / jīng / de / gěi / wán / jù / kàn / bìng / wǒ / rěn / jùn / bù / jīn看到弟弟一本正经地给玩具看病,我忍俊不禁。I could not help laughing when I saw my little brother seriously treating a toy.