Q: What are substances that cannot be broken down into simpler substances with different properties called? Choices: - atoms - compounds - molecules - elements A:
elements

Q: What type of cell layer do flatworms have? Choices: - epidermis - cuticle - endoderm - mesoderm A:
mesoderm

Q: What is the change in a species over time? Choices: - variation - phenomenon - transformation - evolution A:
evolution

Q: Acid rain may be caused by what? Choices: - hurricanes - water pollution - volcanos - air pollution A:
air pollution