1. Tell everyone to be on the alert.

2. Be on the alert for anyone acting suspiciously.

3. Drivers must be on the alert for traffic signals.

4. The city must be on the alert for being polluted.

5. These are the Chinese need to be on the alert.

6. They want to be on the alert for similar buying opportunities.

7. You should always be on the alert for anyone who looks suspicious.

8. Police are warning the public be on the alert for suspicious packages.

9. They should also be on the alert for the attack of typhoon.

10. Police warned the public to be on the alert for suspected terrorists.

11. Police are warning the public to be on the alert for suspicious packages.

12. Admonishing (7 Occurrences) Acts 20:31 Therefore be on the alert; and remember that, night and day, for three years, I never ceased Admonishing every one, even with tears