1) Oxygen 
2) Carbon
3) Hydrogen (water) 
Hope this helps... mark as Brainliest plz
        
             
        
        
        
They can also use carbohydrates so I don't know
        
             
        
        
        
<span>Sir Isaac Newton quantified the gravity between two objects when he formulated his three laws of motion. ... Yet Newton's laws assume that gravity is an innate force of an object that can act over a distance
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In 1905, Albert Einstein determined that the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers. This was the theory of special relativity. It introduced a new framework for all of physics and proposed new concepts of space and time.
Einstein then spent 10 years trying to include acceleration in the theory and published his theory of general relativity in 1915. In it, he determined that massive objects cause a distortion in space-time, which is felt as gravity.
 
        
        
        
Astrocytes are a group  of cells with functional characteristics and distinctive morphological that vary within specific areas of the brain.
For healthy brain function, astrocytes are essential. those become reactive in the case of  Alzheimer's disease, which impacts the signaling properties. while experimenting, there was the measurement for instinctive calcium transients ex vivo in hippocampal astrocytes in brain slices containing the dentate gyrus of  9-month-old  and 6-month-old APPswe/PSEN1dE9  mice. when they investigated the duration of calcium transients and frequency concerning amyloid-β (Aβ) pathology, the proximity of the astrocyte to Aβ plaques, and aging. there was no change in spontaneous calcium-transient properties of 6M APP/PS1 astrocytes compared to wild-type astrocytes, whereas there was hyperactivity in 9M APP/PS1 astrocytes compared to wild -type,  which were longer in duration, also there was an effect of aging too, there was an increase in calcium in the 9-month astrocytes than to the 6-month astrocytes, also there was an increase in the calcium waves in the 9-month astrocytes because of the increase network activity. The findings were that the change in calcium signaling in individual astrocytes of APP/PS1 mice is because of both pathology and aging but these don't have any impact on changes in the astrocyte network activity, which leads to helping to understand changes in neuronal physiology.
To know more about neuronal physiology refer to the link brainly.com/question/17060419?referrer=searchResults.
#SPJ4
 
        
             
        
        
        
D. Scientists use all of the above skills.