Final answer:
Tectonic plates are the pieces of the lithosphere that glide across the asthenosphere due to convection currents.
Step-by-step explanation:
The pieces of the lithosphere that glide across the asthenosphere are tectonic plates. Tectonic plates are large, rigid pieces of the Earth's lithosphere that move slowly over time due to convection currents in the underlying asthenosphere. These plates may interact with each other, causing earthquakes, volcanic activity, and the formation of mountain ranges.
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