See also

Note:
Pinyin#Pinyin tone marking

English version

A leaf is an above-ground plant organ. Its main functions are photosynthesis and gas exchange. A leaf is often flat, so it can absorb more light, and thin, so that the sunlight can get to the chloroplasts in the cells. Most leaves have stomata, which can open and close. They regulate carbon dioxide, oxygen, and water vapor exchange with the atmosphere.

Pinyin version

Yèzi shì dìmiàn shàng de zhíwù qìguān. Tā de zhǔyào gōngnéng shì guānghézuòyòng hé qìtǐ jiāohuàn. Yèzi tōngcháng shì biǎnpíng de, shǐ tā néng xīshōu gèngduō guāng; hé báo de, shǐ tàiyáng guāng néng dàodá tā xìbāo de yèlǜtǐ. Dàduōshù yèzi yǒu qìkǒng, néng dǎkāi hé guānbì. Tāmen yǔ dàqì jiāohuàn, tiáojié èryǎnghuàtàn, yǎngqì, hé shuǐqì.