Conclusion

You have now corrected the whole text. Here it is once again, as it should have been written - with the errors corrected, and with alternatives given in brackets.

Cell phones are becoming indispensable for most of us. Now, a lot of things can be done with a mobile phone. One of these things is geolocalization. This technology of locating is based on the same system as when someone (a person) receives a call. Antenna towers are positioned in each area. There are more antenna towers in urban areas than in rural areas. (...) These antenna towers detect a signal sent by your cell phone and determine where the closest tower is situated (determine the location of the closest tower). The system used to locate someone (people) is triangulation (called / known as triangulation). In conclusion (To conclude), cell phones have strongly evolved and most of us think that cell phones are the future. But we have to be careful with them (they should be used with caution), the waves they send out can be very dangerous.

POUR APPROFONDIR LES POINTS GRAMMATICAUX ESQUISSES DANS LE COMMENTAIRE, CONSULTEZ LES FICHES GRAMMATICALES (DISPONIBLES SUR LE PARCOURS LIBRE).