for better research go to under NOAA - Climate.gov
This is a short paraphrased summary of the article about ice cores in that website.
Answer: Researchers in labs may melt or crush bits of the ice core a little at a time, each deeper layer shows the time in the Earth's climate history. Tiny pieces of pollution, metals, radoiactive fallout, pebbles, sea salt, volcanic ash and even air bubbles all present important information that researchers can look for to track changes in the atmosphere's composition and temperature.
Burning is any fire intentionally ignited to meet specific land management objectives, such as to reduce flammable fuels, restore ecosystem health, recycle nutrients, or prepare an area for new trees or vegetation
Hi there!
The answer is 3., but 1. is VERY close to the correct answer. 1. is incorrect, because the sun's rays do not slant, but the Earth does.
-AwesomeRepublic :)
The model shows that firms and household benefit from one another! hope this helps :)