input: OPTIONS:
- produce off
- Roll over.
- develop off
- reflect off Now, answer this question: Q: What do waves do when they are unable to pass through an object? A:
A:
output: reflect off

Q: Amoebas and paramecia are examples of what? A:

OPTIONS:
- vertebrates
- bacteria
- protists
- protozoa

Answer: protozoa

Problem: OPTIONS:
- liver
- brain
- lungs
- skin
Q: Q: Lacking blood vessels, nerve endings, or glands, the epidermis is the outer layer of what? A:
Answer: skin

Problem:OPTIONS:
- pus
- Blood
- progesterone
- sebum

Q: What kind of oily substance is secreted from sebaceous glands? A:
****
A: sebum

Q: What is the main source of hydrocarbons? A:
OPTIONS:
- photosynthesis
- greenhouse gases
- decomposers
- fossil fuels
fossil fuels

Q: The speed of a wave is a product of its wavelength and what else? A:
OPTIONS:
- voltage
- density
- magnitude
- frequency

Answer:
frequency