[Solved] The first thing a user should do once they start to work within an Excel file is to A) save the workbook. B) create a new worksheet. C) add text. D) create the model. E) add formulas. Phenotype: The set of observable characteristics or traits of an organism resulting from the interaction of its genotype with the environment. Microscopic Characteristics: Features or properties of organisms or substances that are too small to be seen with the naked eye and require a microscope to be observed. Widow's Peak: A V-shaped point on the human forehead hairline due to a specific genetic trait. Straight Hairline: A form of hairline where the hair grows in a straight line across the forehead.