*Question*
Rougher surfaces have more friction between them than smoother surfaces.  Eric rubs together tissue paper and then sandpaper. The rougher tissue paper has less or more friction than the sandpaper?
**Answer**
more

*Question*
To reduce friction, oil is added to the engine.  If Milo's bike chain is not moving well and he adds no oil to it, what will happen to the levels of friction the chain experiences increase or decrease?
**Answer**
increase

*Question*
The bigger the waves are and the more sediment they carry, the more erosion they cause.  A fast-moving river that carries more sediment will cause less or more erosion?
**Answer**
more

*Question*
Areas near the equator are warmer than areas near the poles because they receive more direct sunlight.  Sandra wants to go on vacation, and would like to go somewhere cold. Sandra will likely choose a place near the equator or near the poles?
**Answer**
near the poles