Answer:
The correct answer will be-gas absent in primordial atmosphere (oxygen).
Explanation:
The Miller experiment was performed in 1953 to show that organic molecules can be formed from the inorganic molecules in the conditions resembling the primordial atmosphere.
Same conditions were created to the unstable atmosphere like a mixture of gases which included- methane, sulfur dioxide and hydrogen but lacked oxygen as it was absent in the primordial atmosphere.
Thus, gas absent in the primordial atmosphere (oxygen) is the correct answer.
An enormous cloud of gas and dust that contracts due to gravity and forms stars is called a nebula.
Answer:
the grass grew taller and the hawk population declined
Explanation:
have a good day
Answer:
Yes.
Explanation:
If the graph line comes lowers from 1999 to 2013 so it means that steps taken by the EPA and the factories were effective in reducing air pollution. The steps taken by the EPA and the factories were effective in reducing air pollution occurs from two pollutants i. e nitrogen oxides (NOx) and sulfur dioxide (SO2) if they install chimneys which collect these gases and reduce pollution. if the factories uses coal having less concentration of sulphur so less air pollution occurs.