<span> electricity storage systems readily available. </span>
Plant cells have a cell wall and cell membrane but animal cell have only a cell membrane.
Answer:
At heart, all life on Earth uses a membrane that separates the organism from its environment. ... In this regard, water is essential simply because it's a liquid at Earth-like temperatures. Because it flows, water provides an efficient way to transfer substances from a cell to the cell's environment.
the is a definite article meaning that you cannot use it
"an" can only be used before words beginning with vowels
therefore the answer is" a"
