Why did dinosaurs become extinct?

This a big question that many scientists have asked themselves, however, many of them don't know the true answer to the question. One of their theory's is that an asteroid hit the earth many years ago, resulting in the air being filled with dust and the dinosaurs were not able to react to their surroundings. A lot of the theory's believe that nature activity blocked the pathway of the sun to the earth resulting in the death of lots of animals and plants.

The reason I think they became extinct was because of huge climate changes over time and the inability of the dinosaurs to change. I also think they became a dying species over time. I think that there was once a day when earth was full of loads of species and types of dinosaurs, however, over time they died down and eventually became extinct.

Many discoveries of the history of dinosaurs are still being found to this day and maybe some day the true reason why dinosaurs became extinct will be found.