他从事科学研究。

Tā cóngshì kēxué yánjiū.

He is engaged in scientific research.

教授在进行科学实验。

Jiàoshòu zài jìnxíng kēxué shíyàn.

The professor is performing a science experiment.

老师用很简单的例子来解释这个科学问题。

Lǎoshī yòng hěn jiǎndān de lìzi lái jiěshì zhè gè kēxué wèntí.

The teacher used very simple examples to explain this science question.