下雨的时候，我们就在体育馆里运动。

Xiàyǔ de shíhou, wǒmen jiù zài tǐyùguǎn lǐ yùndòng.

When it rains, we exercise in the gym.

我们下午在学校体育馆上体育课。

Wǒmen xiàwǔ zài xuéxiào tǐyùguǎn shàng tǐyùkè.

We have P.E. class in the school gym this afternoon.

周六体育馆人很多，最好早点去。

Zhōuliù tǐyùguǎn rén hěn duō, zuìhǎo zǎodiǎn qù.

There are many people in the gym on Saturdays, so it’s best to go early.