We need to 'alert' the public 'to' the dangers of these chemicals. [=we need to tell the public about the dangers of these chemicals]
Several neighbors 'alerted' the authorities/police when they noticed strangers acting suspiciously.
The nurse kept/stayed 'alert' for any change [=watched for any change] in the patient's condition.
(..) I have a three-page phone list with every one of our enemies calling to deny responsibility for the attack. Cochrane: All US military bases are on full alert, and the USS Eisenhower is currently hard charging towards the Fifth Fleet stationed in the Persian Gulf. I understand alerting our bases, (..)2016 TvShow: Designated Survivor Title: Pilot Season: 1 Episode 1
(..) Still too early to determine. We got to give them something, Karen. The whole world is watching us right now. Exactly. We need to alert every one of our embassies to convey to each host nation that the U.S. is on a war footing and now is not the time to test us. Patch me into -hour (..)2016 TvShow: Designated Survivor Title: Pilot Season: 1 Episode 1