What does phytopharmacology mean? Answer here
What temperature does an egg need to reach before it turns solid? Answer here
Where does the pearly look, called pearlesence, in lipstick come from? Answer here
You write an evaluation essay when you want to present your take on a topic with the hope of possibly getting others to accept your point of view. It is similar to an argumentative essay; however it should be impartial, balanced writing- you're not out to win an argument. With this type of essay you state your thesis and the subsequent paragraphs are to support this thesis.
Do you know how to do something that you find others asking about frequently? Alternatively, are you a quick learner, with a knack for picking up systems, processes, or just general ways of "doing things"? Do you find you can easily explain ways of doing things in a lay-person's terms to others to help them accomplish tasks? If so, you're the perfect candidate for writing a How-To Essay. If not, you can certainly learn how to write a How-To Essay, so that you can pass your knowledge on to others and inspire them to "get at it."