上课的时候不要忽视老师的话。

Shàngkè de shíhou búyào hūshì lǎoshī de huà.

During class, don’t ignore what the teacher says.

他忽然想到还有作业没做。

Tā hūrán xiǎngdào hái yǒu zuòyè méi zuò.

He suddenly remembered that he still had homework undone.

天气忽冷忽热，很容易感冒。

Tiānqì hūlěng hūrè, hěn róngyì gǎnmào.

The weather suddenly turns cold and hot; it’s easy to catch a cold.