Scientists have correlated average global temperature with atmospheric carbon dioxide levels for the last 160,000 years using ice cores from Antarctica. How is the carbon dioxide level determined?A. by measuring the CO2 concentration in trapped gases in the ice layers
B. by measuring the 18O/16O ratio in the CO2 molecules
C. by extrapolating the CO2 level from the temperature of the ice
D. by extrapolating the CO2 level from the average global temperature

A. by measuring the CO2 concentration in trapped gases in the ice layers

Explanation:

By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, then, compare past concentrations of greenhouse gasses to temperature.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.