original: The lithosphere is underlain by the asthenosphere, the weaker, hotter, and deeper part of the upper mantle.
simplifications: The lithosphere is over the asthenosphere which is the weaker, hotter, and deeper part of the upper mantle. The lithosphere is above the asthenosphere, the weaker, hotter, and deeper part of the upper mantle. The lithosphere is under the asthenosphere. The lithosphere is under by the asthenosphere. It is the weaker, hotter, and deeper part of the upper mantle. Beneath the lithosphere is the asthenosphere. It is the weaker, hotter, and deeper part of the upper mantle. The lithosphere is over the asthenosphere. That is the weaker, hotter, and deeper part of the upper mantle. The lithosphere is above the asthenosphere, which is the weaker, hotter, and deeper part of the upper mantle. The weaker, hotter, and deeper part of the upper mantle under the lithosphere is called the asthenosphere. The lithosphere is underlain by the asthenosphere. The asthenosphere is the weaker, hotter, and deeper part of the upper mantle. Lithosphere is under the asthenosphere ,which is the weaker ,hotter  and deeper part of the upper mantle