How is hygiene and sanitation, such as handwashing, important to stopping the spread of water-borne illnesses? ( 50 POINTS ANSWER IT AS SOON AS POSSIBLE TO WIN FAST :) ) ( A SHORT ANSWER PLEASE)

Handwashing. It is estimated that washing hands with soap and water could reduce diarrheal disease-associated deaths by up to 50% 1. Researchers in London estimate that if everyone routinely washed their hands, a million deaths a year could be prevented 2.

Explanation:

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.