Write a short essay about the best rotary-wing aircraft ever. It must be a specific aircraft and consist of three paragraphs. In the paragraphs, explain why you chose the aircraft and give important facts about it.

How do we use the sumif formula (when dealing with different formats) ?

Description: write function lastfirst() that takes one argument—a list of strings of the format "lastname, firstname" —and returns a list consisting of two lists: (a) a list of all the last names (b) a list of all the first names

Two students are discussing electricity that has a frequency of 60 hz. student a says that this type of electricity is referred to as ac. student b says that in this type of electricity, the electrons flow in only one direction. which of the following statements is correct? a. only student a is correct b. only student b is correct c. both of the two students are correct d. neither of the two students is correct