(1)pollution
(2)serious
(3)exhaust
(4) percentage
(5)Factories
(6)reduce
(7)scientists
(8)require
1. Yes, they are
2. The pollution problem is as complicated as it's serious.because much pollution is caused by things that benefit people.
3.scientist and engineers
4.Govern ment can pass and enforce laws that require businesses and individuals to stop, or cut down on certain polluting activities