The North Star
Among the pile of stars in the universe, there are a couple that are of great importance to people on Earth. The sun, of course, is one of them. The other is known as Polaris, the North Star. Therefore, it is a great compass(指南针).When people in the northern part of Earth look toward Polaris, they can be certain that they are facing north. The permanence of Polaris in the north sky has helped countless people find their destinations.
Before the invention of modern navigation tools, sailors relied on Polaris. From the top of their ships, sailors would look for Polaris to figure out their place at sea. They figured out the angle between the star and the horizon to determine their latitude(纬度). As long as the equations were not wrong, the results were very reliable. Polaris also let sailors determine North, South, East, and West.
To those who sail at night, changeable storms and dark clouds were more than annoying things. It's possible for a captain to make an accidental wrong turn. The ship could become stranded at sea, and the frustrated captain would have no way to get the ship back on the right course. The sailor's fears wouldn't be relieved until the clouds cleared and Polaris came back into view. Even today, sailors sometimes choose to steer by using Polaris on clear nights.
The Big Dipper, a constellation that is well known in astrology, appears to revolve around Polaris. The handle of the Big Dipper always points to the North Star. When people get lost, it's comforting to know that their problems can be relieved by looking at the sky.
A. It's not difficult to tell the Polaris apart from the pile of other stars in the universe.
B. People who are lost can be relieved by gazing up at Polaris.
C. By knowing directions and their location, sailors could easily steer their ships.
D. They could destroy entire journeys by blocking the view of Polaris.
E. It's certain that the Polaris is part of a constellation(星座), which is not far from it.
F. It is special because it is the only star that always appears to be in the same place in the sky.
