Question

What is true about most higher-grade metallic ores? A. They are usually found deep below Earth's surface—more than 1,000 ft underground. B. Most of them can be extracted using the placer method. C. Most of them can be extracted without requiring blasting. D. They are usually found very close to Earth's surface, less than 1,000 ft underground.

Answer 1

Answer: C - they are usually found deep below earths surface--- more then 1,000 ft underground

Explanation: i just took the test and in the passage they gave it says that the higher grade ores are more expensive because they are deeper into the ground

Answer 2

They are usually found very close to Earth's surface, less than 1,000 ft underground. Option D is correct.

The majority of metallic ores with higher grades are usually found in close proximity to the Earth's surface. This is because mining activities may be more practicable at shallower depths due to the concentration of rich minerals in certain ores that make their extraction commercially viable. Surface mining techniques like as strip mining and open-pit mining are examples of extraction processes.

So, They are usually found very close to Earth's surface, less than 1,000 ft underground

Therefore, option D is correct.