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.
These stars have less mass than the Sun. These stars are farther away from Earth than the Sun is. These stars are made of different chemicals than the Sun. 5). Latoya is studying the stars and she learns that Barnard's star is the third closest star to Earth, although it cannot be seen without a telescope. She also knows that the brightest star in the night sky, Sirius, is much farther away but can be seen by the naked eye.