Answer:
Cross-link is a bond that links one polymer chain to another polymer chain. So cross-linked polymers are polymers that obtained when cross-link bond formed between monomeric units. The cross-linked polymer forms long chains, either branched or linear, that can form covalent bonds between the polymer molecules
Explanation:
Your teacher likes to copy. Found this at https://examples.yourdictionary.com/examples-of-keystone-species.html
Grizzly bears: As predators, bears keep down the numbers of several species, like moose and elk. They also carry and deposit seeds throughout the ecosystem. Bears that eat salmon will leave their dropping and the partially eaten remains that provide nutrients such as sulfur, nitrogen and carbon to the soil.
Answer:
i think the correct answer is b