1. The modification of a stream channel; specifically, the straightening of meanders or dredging of the stream channel to deepen it?

2. CFCs?

3. High-altitude winds circling the poles from west to east?

4. The long-term average weather conditions in a place or region?

5. A place with a high population dentsity, both residential and non-residential, with a business sector?

6. A mixture of finely ground coal and water that is moved by pipiline?

7. The stimultaneous use of a single fuel for the generation of electricity and heat?

8. Any of several map projections based on the projection of the globe onto a cylinder?

9. A generalization suggesting shared, identifing traits uniting two or more culture complexes?

10. A mixture of hydrocarbons that exist in a liquid state in undergroud reserves?