在考试时要聚精会神。

Zài kǎoshì shí yào jùjīnghuìshén.

Concentrate during exams.

他聚精会神地看着比赛。

Tā jùjīnghuìshén de kànzhe bǐsài.

He watched the match with full concentration.

学生们聚精会神地听讲。

Xuéshēngmen jùjīnghuìshén de tīng jiǎng.

Students listen attentively during the lecture.