5. Two _________________ plates are descending (going under) the _________________ plate.
Two oceanic plates are descending (going under) the North American plate.
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5. Two tectonic plates are descending (going under) the overriding plate.
To fill in the blanks and determine the terms for the two plates, we can use our knowledge of plate tectonics.
Plate tectonics is the scientific theory that Earth's outer shell is divided into several large, moving plates. These plates interact with one another at their boundaries, leading to various geological phenomena, such as earthquakes, volcanoes, and the formation of mountain ranges.
One type of plate boundary is called a subduction zone. In a subduction zone, two plates collide, and one plate is forced beneath the other into Earth's mantle. This process creates a region of intense geological activity.
Therefore, in the given statement, the two blank spaces refer to plates involved in a subduction zone. The first plate is the one that is moving below the second plate. So, to complete the sentence:
Two TECTONIC plates are descending (going under) the OVERLYING plate.
In this context, the term "tectonic" refers to the large, rigid sections of Earth's lithosphere that comprise the plates. The "overlying" plate is the one sitting above the descending plate in the subduction zone.