Early 1800's. The Erie Canal was built in 1817
yes it is right according to my research
The ozone layer is part of the Stratosphere
Ozone is the part of Stratosphere that Filtered out the Sun's Ultra Violet Radiation, which protect us from its harmful effect. Without Ozone, we will be exposed to a really high risk of developing skin cancer from the sun's radiation.
Idk if it's right but I looked on three different websites and they all said Africa.
Chemical weathering would be the oxygen reaction.