What allowed humans to settle down in one location and no longer rely on a nomadic lifestyle?
O development of urban areas
invention of agriculture
O
the Green Revolution
the Industrial Revolution

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.

It's between the sagittarius and perseus arms of the milky way.

It's probably because the earth is actually tilted and is not straight when orbiting the sun. that's why when it's winter here, it's summer in the southern hemisphere. in the wintertime in the northern hemisphere, it's colder here because it's tilted away from the sun and the southern hemisphere is tilted closer to the sun (i believe this is the case anyways)

Some of the great contributes to advancement in the us were immigrants