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.
Thus, astronomers use other units of distance. They use light year to measure distances in space the same way we use Kilometers to measure distances on Earth. Now using measure of light year we can comfortably say that the nearest spiral galaxy â Andromeda is 2.3 million light-years away or nearest star to us is about 4.3 light-years away.