Logic of a solution: *Plants exhibit phototropism, or growing toward a light source. Many light sources such as the sun and most artificial lights produce unpolarized light. Plants exhibit phototropism, or growing toward the sun or artificial light.*
*(D)*
The original question: *What is called when plants grow toward the sun or an artificial light?
Options:
- (A) Exfoliation
- (B) Brownian motion
- (C) heat energy
- (D) phototropism
- (E) photovoltaic
- (F) autumn
- (G) peachleaf willow
- (H) mitosis*

Logic of a solution: *Reproduction is the process by which organisms give rise to offspring. Life continues because of reproduction. Life continues because organisms give rise to offspring.*
*(B)*
The original question: *Why does life continue?
Options:
- (A) to use resources
- (B) organisms produce offspring.
- (C) sub-units of species
- (D) things don't die
- (E) the Earth being tilted
- (F) production of energy
- (G) to keep going
- (H) by keeping them warm*

Logic of a solution: *Hydrogen bonds cause water to expand when it freezes. Water is everywhere H20. Hydrogen bonds cause H20 to expand when it freezes.*
*(C)*
The original question:
*What causes h20 to expand when frozen?
Options:
- (A) evaporation
- (B) vaporization
- (C) hydrogen bonds
- (D) helium bonds
- (E) mysterious forces
- (F) nitrogen bonds
- (G) Physical weathering
- (H) precipitation*