It forms a protective and adaptive barrier around a cell and this keeps various bacterial and viral intruders out. They also help in keeping cell systems inside the cell. The shell absorbs viruses and bacteria for nutrients when they do not have a certain strand to get inside the cell or trick it otherwise. Hope this helped!
Its is called intertidal zone
Explanation:
The earth rotation and the moon's pull of gravity causes the tides to rise and fall.High tides occur when the water advances to the furthers point of a shoreline where as low tides happen when the water recedes to the lowest point of the shoreline.Some kinds of animal and plants survive in the ecosystem present between the area of high tides and low tides refered to as the intertidal zone.This area is sometimes covered or uncovered by ocean waters.
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Intertidal zone:brainly.com/question/1346004
Keywords: area, shoreline, high tides, low tides.
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Answer:
1. distance and period of time.
Explanation:
The speed is calculated using the formula 
"k" is the speed, "d" is the distance and "t" is the time.
You need distance and time to calculate the speed.
Speed is how fast an object is going. The direction is irrelevant to speed, not to be confused with velocity, which is speed in a given direction.
