医生警告病人不要吃太多糖。

The doctor ___cautioned the patient against eating too much sugar.

父母应该被警告不要让孩子过度使用社交媒体。

Parents should be ___cautioned about letting their children use social media excessively.

她警告她的朋友地板很滑。

She ___cautioned her friend about the slippery floor.