We all have to stay alert...
He had been spotted by an alert neighbour.
The bank is alert to the danger.
Due to a security alert, this train will not be stopping at Oxford Circus.
He wanted to alert people to the activities of the group...
I was hoping he'd alert the police.
Soldiers and police have been put on alert.
They want to be on the alert for similar buying opportunities.
近义词: alarm,warning signal,alarum2
近义词: qui vive4