A student researching metallurgy has taken notes:

• Bronze Age began when humans learned to alloy copper and tin • Bronze was harder than pure copper • Iron eventually replaced bronze for tools and weapons • Steel is iron alloyed with carbon • Modern alloys combine many elements for specific properties

8
reading

The student wants to explain the importance of alloys in human history.

A

Steel is created by alloying iron with carbon.

B

Alloys transformed human history—from bronze replacing pure copper to launch a new era, to modern alloys engineered for specific properties.

C

Iron eventually replaced bronze for making tools and weapons.

D

Modern alloys combine many elements to achieve specific properties.

Correct Answer: B

Choice B. Bronze Age transformation to modern engineering shows alloys' historical importance.