What do Ice core samples with lower ratios of O-18 to O-16 isotopes tell scientists about past climates? less oxygen content
lower water temperatures
higher water temperatures
more carbon dioxide

Last week i was assigned a thematic. we have groups of three but the people i was assigned with haven't been in school for days. i would appreciate if anyone can me with my thematic . i highlighted most of the important steps and i circled my thematic topic. in desperate need : ( its due on february 19

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled

Are the layers of rock above and below the coal older or younger?