Question

should be very difficult to scratch. in 1812, a mineralogist named friedrich mohs developed a scale to rank the hardness of minerals. the diamond is at the top of the list. not only is it the hardest gemstone, it is also the hardest substance known to humans. rubies and sapphires are the next - hardest gemstones. topaz, quartz, and emeralds are farther down on mohs scale. the scale is useful in ______

• analyzing
• mining
• renewing
• detecting

Explanation:

Mohs' scale ranks mineral hardness. In mining, knowing a mineral's hardness helps determine extraction methods (e.g., harder minerals need specific tools). "Analyzing" is too vague, "renewing" doesn't relate to hardness, and "detecting" focuses on finding, not using hardness. So "mining" is the best fit.

Answer:

B. mining (assuming the options are labeled with letters, but based on the context, the correct option is the one with "mining")