*Question*
If aging is natural, then what is natural? Answer choices: - Spruce - artificial sweetener - aging - wetland - fake purses - wind - imitation crab - Light
**Answer**
aging

*Question*
If the gravitational pull of a natural satellite on Earth's oceans causes the tides, then the pull of what on the Earth's oceans cause the tides? Answer choices: - A yellow star - Time and energy - energy of moving objects - A natural satellite - flow of electrons - An artificial satellite - A red star - hydrogen and oxygen
**Answer**
A natural satellite

*Question*
If pipes can burst because water can expand in low temperatures, then pipes can burst because at low temperatures, water does what? Answer choices: - break off - moves - expand - evaporate - squeeze - flooding - boil - shrink
**Answer**
expand

*Question*
If pigs may compete for territory, water, food, or mates, then what may compete for territory, water, food, or mates? Answer choices: - humans - pigs - Birds - density - gravity - clouds - bears - koalas
**Answer**
pigs