Oral route. Many drugs can be administered orally as liquids, capsules, tablets, or chewable tablets. Because the oral route is the most convenient and usually the safest and least expensive, it is the one most often used. However, it has limitations because of the way a drug typically moves through the digestive tract.
Measuring Distances to Stars. Astronomers use several techniques for discovering how far away an object is. The first is called trigonometric parallax and is based on geometry, but it is only good for up to about 500 light-years.
Scientists will never know the farthest star from Earth, as the star is so far away that its light has not, nor will ever, have enough time to reach Earth. Even the stars within the visible universe are far too numerous to count, but the farthest one that humans have ever detected is about 55 million light years away.