老师提醒学生们注意实验中的潜在危险。

The teacher was ___cautioning the students about potential dangers in the experiment.

老师再三提醒学生们在化学实验时要小心。

The teacher kept ___cautioning the students to be careful during the chemistry experiment.

警察正在警告那个酒后骑自行车的人。

The police officer was ___cautioning the man for riding his bike after drinking.