A personal assistant is someone who assists a specific person with their daily business or personal task. They can have the role of answering phone calls, taking notes, scheduling meetings, etc.
Pure substances- Chemical substance a form of matter having constant chemical composition and characteristic. Mixtures- A material made up of two or more different substances that are not chemically combined
A and b are correct for this problem.
Anaphora because it is the repetition of a word in the start of sentences