Problem:OPTIONS:
- enculturation
- excretion
- thermoregulation
- osmoregulation

Q: In the freshwater flatworms, protonephridia serve chiefly in what? A:
****
A: osmoregulation

Problem:OPTIONS:
- leaf shedding
- leaf multiplying
- leaf coloring
- leaf broadening

Q: Transverse divisions are associated with leaf elongation, and longitudinal divisions are associated with what? A:
****
A: leaf broadening

Problem:OPTIONS:
- particle depth
- density
- color
- size of sediment

Q: How are classic sedimentary rocks group? A:
****
A: size of sediment

Problem:OPTIONS:
- one
- five
- two
- three

Q: How many types of galaxies are there? A:
****
A:
three