他在思考人生。

Tā zài sīkǎo rénshēng.

He's reflecting on life.

这个问题有点难，我要时间思考一下。

Zhège wèntí yǒudiǎn nán, wǒ yào shíjiān sīkǎo yíxià.

This question is a bit difficult—I need some time to think about it.

这条题目测试你的思考能力。

Zhè tiáo tímù cèshì nǐde sīkǎo nénglì.

This question tests your thinking ability.