Answer:
Decomposers are organisms (mostly bacteria and fungi) that break down dead plants and animals, eventually turning them into nutrients that will be added to soil. These nutrients are very important to continue the cycle in the ecosystem. Slugs, earthworms, millipedes, and centipedes also help break down dead things.
Explanation:
I'm not completely sure, but I'm fairly certain that the answer is B.
Hunter-gatherer societies are often nomadic. I believe.
It is in vitro fertilization (IVF).
IVF is a type of assisted reproductive technology used for infertility treatment. It includes the steps like removing an ovum from the woman's ovaries, fertilisation (sperm cell from is injected using a microscopic needle, directly into each harvested ovum from the woman) outside the body, embryo transfer to the same or another woman's uterus after a few days.