Why was it important to establish the Clean Air Act? Select three options
emphasize cost-effective methods to protect the air
encourage people to study the effects of dirty air on human health
determine ways to reduce the number of premature deaths per year
create a regulation that makes any activities that pollute the air illegal
.make sure that no government activities polluted the local atmosphere.

Toorale man murder mystery < - your lab link 1. how was the toorale man found? 2. what did archaeologists learn about the burial? why is the burial important? 3. what information were the scientists able to learn from the skeleton itself? 4. why is the question of whether the injuries came from a stone or steel weapon important? how could scientists distinguish between the different types of weapons? 5. what did the carbon dating and soil testing tell scientists about toorale man? why are the dates interesting for scientists?

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?