天气预报就即将到来的风暴向我们发出了警告。

The weather forecast ___warned us about the approaching storm.

我必须警告你，前面的路非常滑。

I must ___warn you that the path ahead is very slippery.

我的医生告诫我不要吃太多糖。

My doctor ___warned me against eating too much sugar.