The quartz is more resistant to abrasion and chemically more resistant than the feldspar. The result is that the quartz remains in the stream but the feldspar breaks down to clay or is dissolved.
(this is from coursehero.com)
The correct answer is D. The heat from the sun allowed only rocky planets to form in the inner part of the solar system.
Explanation
The inner solar system is the name of the region that includes the inner planets that are characterized by being terrestrial in type, have dense and rocky compositions, few or no moons, and there are no ring systems. Another of its characteristics is that Venus, Earth, and Mars have enough atmosphere to generate climate. On the other hand, the region of the outer planets includes the four most distant planets from the sun, located beyond the asteroid belt, that is, Jupiter, Saturn, Uranus, and Neptune that are characterized by rotating at high speed, have gaseous surfaces, and rings around them (the most notable example is Saturn).
Answer: In Medieval Europe, knights pledged loyalty to vassals, who in turn pledged theirs to powerful lords, and serfs labored in the fields.
Explanation:
A rigid hierarchy refers to one where people who are born into a certain position in life, find it quite hard to move from it or rather one where there are different social classes and people had to be classified in one class for the system to work.
The system during medieval times was much like this. Social classes existed that determined a person's worth in society such as the knights, vassals, Lords and Royals. There was also the serfs who were considered the lowest in the hierarchy.
JOHN DALTON Lived from: 1766-1844 Put forward atomic model in: 1803 Nickname for his model: Billiard Ball Model Description of his model: Dalton was an English chemist and teacher who used experimental evidence to form the atomic theory of matter: All elements are composed (made up) of atoms. It is impossible to divide or destroy an atom.