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.
Neptune is so far away, it's impossible to see without a telescope. Because Pluto has such a weird orbit, Neptune is actually the furthest planet from the sun for 20 years out of every 248 Earth years. Pluto moved out of the way for Neptune at the end of the 20th century.