Question

1. which discovery(ies) helped scientists understand how plates could move?

a. the discovery of earth’s core
b. the discovery that new crust is made in the middle of the oceans
c. the discovery that old crust is destroyed in trenches
d. both b and c

Explanation:

To determine which discovery helped scientists understand plate movement, we analyze each option:

• Option a: The discovery of Earth’s core is related to Earth’s internal structure but not directly to plate movement mechanisms.
• Option b: New crust formation at mid - ocean ridges (seafloor spreading) shows how plates can move apart as new material is added.
• Option c: Old crust destruction in trenches (subduction zones) shows how plates can move towards each other and be recycled.
• Option d: Since both the formation of new crust (option b) and destruction of old crust (option c) are key processes in plate tectonics that explain how plates move (seafloor spreading and subduction working together), this option is correct.

Answer:

d. Both b and c