Answer:
(01) D
(02) E,C.
Explanation:
(01) the growing number of people in the cities puts a strain on waste management efforts. If a city cannot effectively cope, this will mean poor management which will strain the condition of our environment further. it can cause diseases especially in poor areas.
Oxygen entered the Earth's atmosphere after the appearance of the Great Oxidation Event (Great Oxygenation Event). The Great Oxidation is the first mass extinction on Earth.
The Great Oxidation lasted 2.4 to 2.0 billion years ago.
Oxygen appeared on Earth thanks to cyanobacteria using photosynthesis.