| 1 | The attraction of the moon for the earth causes the tides. | |
| 2 | Some scientists are hard at how use of tidal power. | |
| 3 | There are spirits in currents and tides, in coral reefs and mangroves. | |
| 4 | Now researchers have found an extreme version of tidal forces at work. | |
| 5 | While swimming you always need to be aware of rip tides and rip currents. |