What primarily set off large-scale migration flows among European countries during the twentieth century?
A. The ability to establish distinctive political structures
B. The familiar cultural traditions of the host countries
C. The motivation to reach quotas set by individual countries.
D. The desire to reunite with family members who migrated previously
E. The removal of migration restrictions

Answer:

Because the gravity of the Earth is pulling on air molecules and pressing it against the ground, our atmosphere is thinner and thinner the higher up you go.

Explanation:

Earth is a planet that has an active core, thus it has a reasonably strong gravitational pull. Gravity manages to keep all things on the surface of our planet and the ones that are in the atmosphere to pull them down or keep them near. This affects the atmosphere as well.

The atmosphere is composed of gases, all of which are made out of atoms and molecules. They are very light, so Earth is pulling them towards it. This has resulted in a situation where the majority of the gases are close to the surface, in the lowest parts of the atmosphere, and as we go up there is less and less of them, so the atmosphere is thinner and thinner as the elevation increases.

Answer:

C

Explanation:

its the only scientifically proven and logically reasonable answer

Answer:

C

Explanation:

I'm not 100% sure though

Answer:

They help us to develop new technologies and are used in our everyday lives. Our use of rocks and minerals includes as building material, cosmetics, cars, roads, and appliances. In order maintain a healthy lifestyle and strengthen the body, humans need to consume minerals daily.

Explanation:

Rocks and minerals are all around us! They help us to develop new technologies and are used in our everyday lives. Our use of rocks and minerals includes as building material, cosmetics, cars, roads, and appliances. In order maintain a healthy lifestyle and strengthen the body, humans need to consume minerals daily. Rocks and minerals play a valuable role in natural systems such as providing habitat like the cliffs at Grand Canyon National Park where endangered condors nest, or provide soil nutrients in Redwood where the tallest trees in the world grow.

Rocks and minerals are important for learning about earth materials, structure, and systems. Studying these natural objects incorporates an understanding of earth science, chemistry, physics, and math. The learner can walk away with an understanding of crystal geometry, the ability to visualize 3-D objects, or knowing rates of crystallization.

Natural objects, such as rocks and minerals, contribute to the beauty and wonderment of the National Parks and should be left, as they were found, so that others can experience a sense of discovery.

source google