Until the early Proterozic there were only negligible amounts of free oxygen in the atmosphere
Answer:
C
Explanation:
When immigrants arrived to the East Coast of the United States in the 19th Century, they tended to move into neighborhoods in which members of their nationality already lived.
This was practical as the immigrants would be able to assimilate easier and would not feel as isolated in the new country. The established immigrants could also be a useful source of information and could help in difficult times.
These neighborhoods were located in the large East Coast cities and came to be small representations of the home country of the immigrants that founded them.
Greenhouse emissions of tar sand, per barrel, are more than conventional crude oil. This is because, it takes more energy to extract the bitumen from the tar sand and more so, to convert the bitumen to usable oil taking up even more energy. This energy is usually derived from burning natural gas. Emissions by tar sand are approximately 100 kg CO2 per barrel while conventional oil is approximately 30 kg CO2 per barrel.
Answer:
Hi! It's C. Moving to a new state.
Explanation:
A, B, and D are about things that happen temporarily. Moving to a new state is long term.
