D.
Different parts of the sun lit moon become visible as the moon revolves around earth
This happens because as the moon orbits earth the sun will project light towards it and the reason it seems to glow is because of the reflected light since the moon is white it reflects more light. Think of it as a day and night cycle except it’s on the moon when it becomes night on earth the part of earth facing towards the sun will be lit aka day/morning/afternoon etc
The part of the earth facing away will be dark aka night/midnight/etc.
The types of elements that are present
The correct answer is: A. How does changing the amount of water affect the growth of corn?
While options B, C & D are not impossible to test, option A is the only question that can be tested using quantitative methods, such as statistical analysis. The question in option A states: "How does changing the amount of water affect the growth of corn?". This question is easily testable using scientific investigation, because controlled or measured amounts of water can be added to corn, and the consequent growth rate of corn can be easily measured and recorded. However, the questions in options B, C & D cannot be precisely measured using quantitative tools, since they aim to measure qualitative (subjective) factors, such as: ethics, happiness and disappointment.
Explanation:
The melting point is the temperature at which solid substance turns to a liquid phase. However, not all substances observe this change in phase. Some sublimate- which is the turning from solid to gas without transiting the liquid phase. Such substances are; dry ice (solid CO2), arsenic, naphthalene, and iodine.