The correct statement is the fourth one. The riverbed erodes into a V-shaped valley while the glacier erodes into a U-shaped valley. Glaciers and rivers have tributaries or small rivers that join the main river. For glaciers, as it erodes deeper, the small river is left higher up the steep sides. For rivers, as it erodes, ridges of land form in its upper course.
The Earth's magnetic reversals are likely due to changes in the circulation patterns of materials in the outer core. This phenomenon is also referred to as geomagnetic reversal and involves the interchanging of position of the magnetic north and the magnetic south. The reversal can occur within a span of 0.1 to 1 million years. It is primarily driven by the dynamic movement of the molten iron found on the outer core that then generates electric currents, thereby, producing magnetic fields.
Recombinant DNA is the answer
It will become a manonamer organism
