sentence: Canals usually connect lakes, rivers, or oceans.
sentences_before: A 'canal' is a waterway made by humans. In the 1800s and 1900s, canals were built as a way of transporting heavy goods in barges.
sentences_after: Some canals allow boats to pass. Others are used for irrigation. The Panama Canal is a famous canal that connects the Atlantic Ocean with the Pacific Ocean. They are inforced with clay or concrete on the sides.
concept_name: canal
headings: Canal