Where does the first stage of respiration take place?

the answer is c cumulus. cumulus clouds can be seen on a gray and rainy day, because cumulus clouds create thunderstorms. give me brainliest if right.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u

the answer would be d : p