Question

which sentence best describes a central idea of the section titled air pressure? mercury reacts better to air pressure than water does. experiments prove that water rises in a tube due to the air pressure around it. the heaviness of liquids determines how much air pressure influences them. the ancient greeks and romans conducted experiments to study air pressure.

Explanation:

The image shows a mercury - barometer setup related to air pressure. Option B focuses on the principle of air - pressure causing liquid (water in this case) to rise in a tube, which is a central concept in understanding air pressure. Other options are either not central (like comparison of mercury and water in option A), not relevant to the main idea (option C about liquid heaviness), or not the main focus (option D about ancient experiments).

Answer:

B. Experiments prove that water rises in a tube due to the air pressure around it.