And although you can't build from Planning Sets, they will allow you to gather bids from contractors, arrange your furniture in the plan, analyze traffic patterns and gauge the site lines on your lot.
A: Earth's atmosphere, which is around 300 miles thick, is mainly made of nitrogen and oxygen, although there are many other trace substances in its composition. Trace substances make up only 1 percent of the bulk of the atmosphere while nitrogen (78 percent), oxygen (21 percent) and argon (1 percent) make up the rest. Continue Reading
Air is made almost entirely of two gases. The most common gas is nitrogen, and the second most common gas is oxygen (O2). Nitrogen and oxygen together make up 99% of the planet's atmosphere. All other gases together make up the remaining 1%.