1.   Air pollution is our most serious environmental problem.

2.   But that could cause other environmental problems.

3.   Developed countries must bear much of the responsibility for environmental problems.

4.   Energy management Science offers a key to solving environmental problems by providing more data to construct better predictive models.

5.   Environmental problems are now a central concern.

6.   Environmental problems relating to the factory have yet to be addressed.

7.   In many wealthy countries, waste is the environmental problem that people care about most.

8.   In the meantime, we will protect consumers against high prices and poor service and give greater priority to environmental problems.

9.   She emphasized the growing need to deal with environmental problems.

10.   The government seems confident that environmental problems can be fixed.