Treating wastewater can be expensive for starters. A community may not need the water and therefore wouldn't wanna waste their time and money converting it. Some places do not have a storage place for the clean water so they would only be cleaning it to re-pollute it.
As hinted in the question, the cross bridge cycle is a
series of molecular events that occur after excitation of the sarcolemma. A
cross bridge is formed when a myosin head bound to actin. The cross bridge
cycle depends on the presence of calcium ions
Perform regular resistance exercise
Step number 5 analyze data and draw a conclusion.