Name one example of the three most common operating systems for personal computers.

Which type of excel chart should be used to track students’ progress on test grades? line column bar pie

Does the query hawaiian photographers fully meets results?

Implement a document scanning function wordcountengine, which receives a string document and returns a list of all unique words in it and their number of occurrences, sorted by the number of occurrences in a descending order. if two or more words have the same count, they should be sorted according to their order in the original sentence. assume that all letters are in english alphabet. you function should be case-insensitive, so for instance, the words “perfect” and “perfect” should be considered the same word.