Answer:
Electron microscope would be used for if,
C) details of cell structures needed to be distinguished.
Explanation:
- The general principal of electron microscopy is analogous to light microscopy except that it uses electrons to analyse the specimen instead of light.
- Electron microscopy focuses a beam of electron on the target sample and records the difference in absorption by different surfaces.
- Electron microscopy is used to get the detailed structure of cells and surface features of various viruses and bacteria.
- However, it is not possible to view living biological samples through electron microscope because high velocity electron have immense energy to kill living cells.
- These samples are thus, fixed and then viewed.
Answer:
The correct answer would be 0.85 liters.
It can be explained with the help of unit rate that is, when the rate is expressed as the quantity of 1 for example, 5 meter per second, 5 liters per day et cetera.
In this case, unit rate (liter per day) can be calculated by dividing the total amount of water used by total number of days.
Amount of water used in 28 days = 23.8 liters
The amount of water used in one day = 
It comes out to be 0.85 liters per day or 850 milliliter per day.
Adenine pairs with thymine (or uracil), and guanine pairs with cytosine.