سؤال قراءة ستيب محلول — الإشارة والمرجعية (تدريب 6362)

(1) Fish are cold-blooded vertebrates that live in water. They differ greatly in size, shape, color and habits. Some fish may look like worms, while others may resemble resemble rocks. All the colors of the rainbow can be found in fish. Some fish are very brightly colored while others can be very dull. (2) Fish can live in almost any conditions of water. They can live in the freezing waters of Antarctica, hot jungle streams, lakes and fast flowing mountain rivers. Nearly all fish get their oxygen from water. Although we cannot see it, water does contain oxygen. To get this oxygen, the fish forces water through its gills. The gills absorb oxygen and release carbon dioxide into the water which then passes out through the gills. (3) Scientists have found over 21,000 different kinds of fish. They continue to find more species each year. Scientists who study fish are called ichthyologists. Fish are truly amazing animals to study and observe. What is the main idea of the passage?