When Amanda poured some of the liquid in a test tube, she noticed that the edges if the water curved upward, which is an illustration of adhesion.
When Pol filled another test tube to the top, the liquid formed a low dome, which is a proof of cohesion.
When Amanda added table salt to the first test tube and shook it, she noticed that the liquid had dissolved the solute.
All of these observations are suggesting the existence of covalent bonds.
Pol determined that the pH of the sample is 7 that indicates that the sample is neutral.
Based on all the proof gathered by Pol and Amanda, the unknown liquid is water.