Problem: OPTIONS:
- stratosphere
- air
- troposphere
- clouds
Q: Q: Where do lightnings build up? A:
Answer: clouds

Problem:OPTIONS:
- dermis
- callus
- cartilage
- epidermis

Q: A hair grows out of a follicle and passes through what before extending above the skin surface? A:
****
A: epidermis

Q: The temperature at which something melts is refered to as what? A:
OPTIONS:
- precipitation point
- evaporation point
- boiling point
- melting point
melting point

Q: Energy from sunlight enters many ecosystems through what process? A:
OPTIONS:
- multiplication
- reproduction
- isolation
- photosynthesis

Answer: photosynthesis

Question: Q: What is the smallest unit of time commonly based on? A:
OPTIONS:
- hour
- millimeter
- minute
- second
Answer: second

input: OPTIONS:
- hormones
- virophages
- byproducts
- enzymes Now, answer this question: Q: What proteins synthesized in cells act as catalysts? A:
A:
output:
enzymes