Cloning endangered species is a good idea?

Cloning does Not work, except for plants. If a species is Extinct, it is gone forever. The only way cloning could bring back an extinct species such as the Dinosaurs, according to the PBS Science Show: Nova, hosted by Jeff Goldblum, (from Jurassic Park), is If we were to spend Billions of dollars to make it happen. It is Possible to bring an extinct species back to life by cloning, but, no one is going to spend Billions of dollars to bring an extinct species of life back from the dead. It is Possible, but, it is Not Practical, and It is not Affordable, so it is Never going to happen.