Read the article "Past and Present Ships:" The ship has been used to travel across waterways for thousands of years. The methods, tools, and purposes of ships have changed greatly from the age of exploration to the present.
When explorers sailed to the new world, ships were built with multiple masts and many sails. Wind caught the sails and sped the boat along. In order to harness more of the wind's energy, ship builders increased the size of the sails, which also increased the speed of the ships. The placement of the sails also allowed sailors to control the direction of the boat, even when the wind was not behind the ship. Unlike these wind-powered ships, today's ships are powered by gas turbines or diesel engines. The energy produced by either substance turns the ship's propellers, moving it in a specific direction. Instead of masts and sails, these ships have stacks of funnels that release steam and smoke from the engines.
Another area of difference between past and present ships is the tools that are used. Explorers could only use maps of areas that had been previously explored. In order to sail to new lands, navigation tools were developed. Magnetic compasses pointed north, which positioned sailors and helped them to head in a chosen direction. Explorers and sailors used a variety of tools to find the latitude of the ship. The astrolabe helped them find latitude by measuring the angle of the sun. The more accurate sextant replaced the astrolabe, as it found the latitude of another ship by measuring the angle between the sun and the horizon. Other tools included the cross staff, the back staff, and the quadrant. Today's ships continue to use compasses and maps. However, sailors frequently navigate using digital maps available on the internet or a Global Positioning System. The many calculations needed to identify a ship's location are done by computers. Furthermore, present ships have the added advantage of radar. Radar sends out radio waves and records the reflective waves. Sailors use radar to avoid hitting other ships or objects in the water.
Finally, the purposes of ships have changed over time. Early explorers used seaworthy ships to discover new lands. In contrast, people who want to explore other countries can take cruises. In the past, ships transported people and goods from one place to another, especially for trade. Colonies would send natural resources and raw materials to other countries. Common items included fish, furs, lumber, cotton, and sugar. Today's ships are still used for transportation and trade. Ferries are used to transport people and cars across waterways. Container ships transport massive boxes of manufactured goods between nations. Bulk containers move raw materials, while tankers ship oil and petroleum to different countries. The ship's purposes are the same, but the ways in which they accomplish their goals are different.
For centuries, ships have brought news of discoveries to the world. The differences between past and present ships make one similarity very clear: ships connect people and change the world.

Read the article "The Impact of Boating:"
Many people enjoy boating on rivers, lakes, and oceans. Boats with motors are often used for these types of activities. Unfortunately, the boating has serious consequences for the environment. Boat engines usually run on oil or fuel. These fluids have the potential to spill or leak into the water. Once in the water, oil and fuel tend to stay on the surface of the water. These harmful liquids poison fish, birds, and other wildlife. People work y can endanger other plants and animals. As a result, some boaters have begun drying their boats before moving from one body of water to another. Boating is a fun, enjoyable activity, with a lot of responsibility. Boaters need to take care of their boats in order to reduce their impact on the environment.

Select sentences from each text that demonstrate the difference in text structure.

A. Container ships transport massive boxes of manufactured goods between nations. The sun feels warm on the skin, the fresh air smells wonderful, and the lapping of
the waves is soothing.

B. Common items included fish, furs, lumber, cotton, and sugar. When the United States realized the severe impact of oil and fuel on waterways, there were laws passed, making it illegal to put oil or fuel in U. S. waters.

C. Unlike these wind-powered ships, today’s ships are powered by gas turbines or diesel engines. As a result, some boaters have begun drying their boats before moving from one body of water to another.

D. In contrast, people who want to explore other countries can take cruises. Many people enjoy boating on rivers, lakes, and oceans