1: to tell if a tsunami is coming look at the waves if the wave is pulling back in a very long distance away from you start running but if the waves are big or just small they should be okay to swim in.

3: If your in a scary place and want to know if your being watched in a mirror you can place your finger on on the mirror and if there's a gap between your finger and the reflected mirror it's safe but if the mirror is basically connected your being watched.

4: if you want to know if there's cameras in a place your staying cut off all the lights and flash a light in the room if you see a small shinning circle or anything like that it most could possibly be a camera.