1) What gas needed to be established within the Earth's atmosphere before 1 point the atmosphere was able to absorb and maintain heat? Hydrogen
Nitrogen
Oxygen
Carbon dioxide

When studying the calumet region of illinois and indiana alfred meyers noted four stages of development as new groups occupied this land in stage 2 farmers used the land primarily to grow food for their familes and their small communities

How many time zone are there on earth

Many rivers in central asia come from