2011年高考阅读理解真题——科普知识类

Humpback whales are sometimes called performers of the ocean. This is because they can make impressive movements when they dive. The name “humpback”, which is the common name for this whale, refers to the typical curve shape the whale’s back forms as it dives.

Sometimes the humpback will dive with a fantastic movement, known as a breach. During breaching the whale uses its powerful tail flukes to lift nearly two-thirds of its body out of the water in a giant leap. A breach might also include a sideways twist with fins stretched out like wings, as the whale reaches the height of the breach.

A humpback whale breathes air at the surface of the water through two blowholes which are located near the top of the head. It blows a double stream of water that can rise up to 4 meters above the water.

The humpback has a small dorsal fin located towards the tail flukes about two-thirds of the way down its back. Other distinguishing features include large pectoral fins, which may be up to a third of the body length, and unique black, and white spots on the underside of the tail flukes. These markings are like fingerprints: no two are the same.

Humpback whales live in large groups. They communicate with each other through complex “songs”.

Quick Facts

 Size:

14m~18m in length

30~50 tons in weight

Living environment:

Open ocean and shallow coastline waters

Migration:

From warm tropical (热带的) waters, where they breed, to cold polar waters, where they eat.

Diet:

Shellfish, plants and fish of small size

Hunting:

Sometimes in groups, in which several whales form a circle under the water, blowing bubbles that form a “net” around a school of fish. The fish are then forced up to the surface in a concentrated mass.   

Current state:

Endangered: it is estimated that there are about 5000~7000 humpback whales worldwide.According to Quick Facts, a humpback whale ______.