Is the paleozoic era is the longest time period in the history of earth?

Number and variety of living organisms includes genetic, species, and ecological types

What must be done to breed dogs for a partical trait

[34 points awarded to the best answer, use facts and/or data] 1.) what's the likelihood of thunderstorms occurring in the state of maryland? {this question is for a project for science, use facts and/or data and explain why . 34 points to the best answer]