Over time, the types of technology can vary and be improved upon so that more advanced techniques become more valued. This could be the situation with mining whereby back in the 1500's in underground mines the rock was broken by fire setting ie lighting a fire below the rock face to heat up the rock and then throwing cold water on it to crack it, so that it could be dug by hand. With the advent of explosives, this all changed so that the rock could be blasted. The increase in advance rates for an underground heading have thus gone from 5-20 feet per month to up to 300meters (984 ft) per month for a 24/7 mining operation, which is a huge improvement.
Answer:
C
Explanation:
light can travel in a vacuum Anne the sped varies
B. truthfully it's the only one that makes sense
Answer:
A
Explanation:
A. The molecules that make up olive oil are longer than those that
make up alcohol, so they have more resistance to sliding past one
another.
Olive oils are unsaturated fats with many carbons whereas, alcohols are typically short with very few carbons.
Answer:
Color, however, is the least useful property for mineral identification. One reason is that many minerals have similar colors. Also, impurities can turn colorless minerals into colored minerals.
Explanation:
