Answer:
a
Explanation:
its a limitation not a bost have a good day
i think it is D, she has already constructed the hypothesis and needs is performing the experiment. there is not much of an observation stage because she is looking at a distant end result in a set time frame.
The Hertzsprung-Russell diagram is one of the most important tools in the study of stellar evolution. Developed independently in the early 1900's by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the color of stars against their absolute magnitude
Depending on its initial mass, every star goes through specific evolutionary stages dictated by its internal structure and how it produces energy. Each of these stages corresponds to a change in the temperature and luminosity of the star, which can be seen to move to different regions on the HR diagram as it evolves. This reveals the true power of the HR diagram – astronomers can know a star’s internal structure and evolutionary stage simply by determining its position in the diagram.
The Hertzsprung-Russell diagram the various stages of stellar evolution. By far the most prominent feature is the main sequence (grey), which runs from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) of the diagram. The giant branch and supergiant stars lie above the main sequence, and white dwarfs are found below it.
Answer: The means for transmission of disease-causing microorganism is provided by the direct or indirect contact.
Microorganisms can cause disease only once they are transferred to the body. The disease causing microorganisms are termed as pathogens which are transmitted by several ways such as from skin to skin, by nuclei droplets, through blood and body fluids or via air. In vector transmissions the disease is carried by the parasitic insects via animals, air borne transmission occurs when microorganisms move through air or the dust particles, droplet transmission occurs by coughing, sneezing or talking by the person who is infected while indirect transmission occurs by physical contact or by touching contaminated objects.