Rules for when you use "a" "an" and "the"

When should you use encyclopedias such as wikipedia? a. never, it is not appropriate to use this source in college b. it can you get an overall understanding of the subject matter but is not considered a college-level source c. as long as wikipedia isn't the only source, it is always appropriate to use this source

“heartwork each day is born with a sunrise and ends in a sunset, the same way we open our eyes to see the light, and close them to hear the dark. you have no control over how your story begins or ends. but by now, you should know that all things have an ending. every spark returns to darkness. every sound returns to silence. and every flower returns to sleep with the earth. the journey of the sun and moon is predictable. but yours, is your ultimate art.” ― suzy kassem what does this quote mean to you? and why? i'm not looking for anything in particular, i just wanted to know. : )

Read the passage. (1) since prehistoric times, milk has been a vital source of nutrition for human beings. (2) some doctors and nutritionists believe that consuming milk can be detrimental to our health. (3) milk is one of the most nutrient-dense beverages we can consume and it should be an essential part of a healthy diet. (4) drinking just one 8-ounce glass of milk per day puts you well on your way to meeting recommended daily intakes for important nutrients. which transition would be best to use at the beginning of sentence 2? finally additionally however specifically