What does the passage mainly discuss?

The word “it” in paragraph 3 refers to ........

The handling and delivery of mail has always been a serious business, underpinned by the trust of the public in requiring timeliness, safety, and confidentiality. After early beginnings using horseback and stagecoach, and although cars and trucks later replaced stagecoaches and wagons, the Railway Mail Service still stands as one of America’s most resourceful and exciting postal innovations. This service began in 1832, but grew slowly until the Civil War. Then from 1862, by sorting the mail on board moving trains, the Post Office Department was able to decentralize its operations as railroads began to crisscross the nation on a regular basis, and speed up mail delivery. This service lasted until 1974. During peak decades of service, railway mail clerks handled 93% of all non-local mail and by 1905 the service had over 12,000 employees. Railway Post Office trains used a system of mail cranes to exchange mail at stations without stopping. As a train approached the crane, a clerk prepared the catcher arm which would then snatch the incoming mailbag in the blink of an eye. The clerk then booted out the outgoing mailbag. Experienced clerks were considered the elite of the Postal Service’s employees, and spoke with pride of making the switch at night with nothing but the curves and feel of the track to warn them of an upcoming catch. They also worked under the greatest pressure and their jobs were considered to be exhausting and dangerous. In addition to regular demands of their jobs they could find themselves the victims of train wrecks and robberies. As successful as it was, “mail-on-the-fly” still had its share of glitches. If they hoisted the train’s catcher arm too soon, they risked hitting switch targets, telegraph poles or semaphores, which would rip the catcher arm off the train. Too late, and they would miss an exchange.

Which of the following can be inferred from the first paragraph?

According to the passage, the benefit of listening to music while learning and studying is that it ..............

Each person has different learning preferences and styles that benefit them. Some may find they have a dominant learning style. Others prefer different learning styles in different circumstances. There is no right or wrong answer to which learning style is best for you - or mix of learning styles. However, by discovering and better understanding your own learning styles, you can employ techniques that will improve the rate and quality of your learning. If you prefer lessons that employ images to teach, you are a visual learner. Visual learners retain information better when it is presented in pictures, videos, graphs and books. They frequently draw pictures or develop diagrams when trying to comprehend a subject or memorize rote information. If you are a visual learner, use pictures, images, color, diagrams and other visual media in your note taking, test preparation and studying. Whenever possible, use pictures instead of text. Try to develop diagrams to comprehend concepts and storyboards to remember important sequences and relationships. Aural (auditory) learners retain information better when it’s presented in lecture format, via speeches, audio recordings, and other forms of verb communication. While a visual learner would prefer to read a book or watch a video, auditory learners would prefer to attend a lecture or listen to a book on tap. Aural learners are also big on sound and music. They can typically sing, play an instrument and identify different sounds. If you are an aural learner, integrate auditory media, listening techniques, sound, rhyme, or even music in your learning and studying. You may also consider using background music and sounds to help you with visualization of processes and systems. For example, if you’re practicing fight procedures, you may consider playing a recording of an aircraft in the background as you study. Replacing the lyrics of a favorite song with information you are learning is a very powerful way to memorize large amounts of information for aural learning. Use this technique and you will never forget the information again. 

What does the passage mainly discuss?

The word “metamorphosis” in paragraph 2 is closest in meaning to................

Today, roller skating is easy and fun. But a long time ago, it wasn't easy at all. Before 1750, the idea of skating didn't exist. That changed because of a man named Joseph Merlin. Merlin's work was making musical instruments. In his spare time he liked to play the violin. Joseph Merlin was a man of ideas and dreams. People called him a dreamer. One day Merlin received an invitation to attend a fancy dress ball. He was very pleased and a little excited. As the day of the party came near, Merlin began to think how to make a grand entrance at the party. He had an idea. He thought he would get a lot of attention if he could skate into the room. Merlin tried different ways to make himself roll. Finally, he decided to put two wheels under each shoe. These were the first roller skates. Merlin was very proud of his invention as he dreamed of arriving at the party on wheels while playing the violin. On the night of the party Merlin rolled into the room playing his violin. Everyone was astonished to see him. There was just one problem. Merlin had no way to stop his roller skates. He rolled on and on. Suddenly, he ran into a huge mirror that was hanging on the wall. Down fell the mirror, breaking to pieces. Nobody forgot Merlin's grand entrance for a long time! 

The passage is mainly about ..................