How do major events help geologists organize Earth’s history?

There are two important tools that geologists use to portray the history of the Earth: the geologic time scale and paleogeographic maps. The geologic time scale is a standard timeline used to describe the age of rocks and fossils, and the events that formed them.

Explanation:

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

d.embryo is the correct one