Respuesta :
Answer:
The correct answer for this question is D) Over time the sand bed will become plugged with dirt and require a cleaning process known as backwashing.
Explanation:
This sentence best fits at the end of the topic as it explains that one stage of the maintenance process is the backwashing of the item.
Answer:
D) Over time the sand bed will become plugged with dirt and require a cleaning process known as backwashing.
Explanation: