Problem: OPTIONS:
- amino acid
- acetic acid
- carbonation
- citric acid
Q: Q: What in orange juice makes it taste sour? A:
Answer: citric acid

Problem:OPTIONS:
- mammals
- enzymes
- spiders
- insects

Q: More than half of all known organisms are what? A:
****
A: insects

Q: What causes fertilization to occur? A:
OPTIONS:
- accumulation and an egg fuse
- tissue and an egg fuse
- genetic and an egg fuse
- sperm and an egg fuse
sperm and an egg fuse

Q: Halides of the transition metals become more covalent with increasing oxidation state and are more prone to what? A:
OPTIONS:
- comproportionation
- cycloaddition
- decarbonylation
- hydrolysis

Answer: hydrolysis

Question: Q: What is the term for the movement of individuals out of a population? A:
OPTIONS:
- succession
- colonization
- immigration
- emigration
Answer: emigration

input: OPTIONS:
- differential
- network
- worker
- operator Now, answer this question: Q: When lactose is absent, a repressor protein binds to what? A:
A:
output:
operator