*Question*
If a tree falls then sunlight becomes available to the surrounding plants, and oak trees are found throughout. Given these facts, what falls making sunlight available to surrounding plants among the following options: - LEDs - grass - elms - oak - pine - clouds - palm - acorns
**Answer**
oak

*Question*
Burning fossil fuels increases the carbon in the atmosphere, and more carbon in the atmosphere means atmospheric warming. Given these facts, what increases when fossil fuels are burned among the following options: - Greenhouse gasses - Greenhouse gases - cancer - wood ash - atmospheric warming - coal - heat energy - Temperature
**Answer**
atmospheric warming

*Question*
Amirror is used for reflecting light, and light is the visible form of electromagnetic energy. Given these facts, what does a mirror reflect among the following options: - our nearest star - focusing a lens - kinetic energy - sound waves - sun's heat - heat energy - body water - visible energy
**Answer**
visible energy

*Question*
Population density is the average number of individuals per unit of area or volume, and density is the population divided by the area. Given these facts, what is the average number of individuals per unit of area or volume among the following options: - population divided by class - population divided by area - solid, liquid, gas - biological diversity - competing for resources - population divided by income - population divided by wealth - Something that makes plants green
**Answer**
population divided by area