做面包的时候需要加一点酵母。

Zuò miànbāo de shíhou xūyào jiā yīdiǎn jiàomǔ.

You need to add a little yeast when making bread.

酵母在温暖的环境中发酵得更快。

Jiàomǔ zài wēnnuǎn de huánjìng zhōng fājiào de gèng kuài.

Yeast ferments faster in a warm environment.

我们在生物课上用显微镜观察了酵母。

Wǒmen zài shēngwù kè shàng yòng xiǎnwēijìng guānchále jiàomǔ.

In biology class, we observed yeast under a microscope.