Hurry pleas Which 2 events during meiosis increase GENETIC
VARIATION by ensuring that each egg and each
sperm will be unique?

(three) crossing over, mutations caused during crossing over, and independent assortment.

Explanation:

Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote. Recombination or crossing over occurs during prophase I.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

i think the answer is b.