题目
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参考答案及原文
答案：
31. 795
32. tail
33. floor
34. sense of smell
原文：
Today we’re going to look at one of my favourite fish - the shark. As you know, sharks have a reputation for being very dangerous creatures capable of injuring or killing humans, and I’d like to talk about sharks in Australia.
Sharks are rather large fish, often growing to over ten metres and the longest sharks caught in Australia have reached sixteen metres. Sharks vary in weight with size and breed, of course, but the heaviest shark caught in Australia was a White Pointer - that weighed seven hundred and ninety-five kilograms - quite a size! Sharks have a different structure to most fish: instead of a skeleton made of bone, they have a tough elastic skeleton of cartilage. Unlike bone, this firm, pliable material is rather like your nose, and allows the shark to bend easily as it swims. The shark’s skin isn’t covered with scales, like other fish: instead the skin’s covered with barbs, giving it a rough texture like sandpaper. As you know, sharks are very quick swimmers. This is made possible by their fins, one set at the side and another set underneath the body, and the tail also helps the shark move forward quickly. Q31 Q32
Unlike other fish, sharks have to keep swimming if they want to stay at a particular depth, and they rarely swim at the surface. Mostly, they swim at the bottom of the ocean, scavenging and picking up food that’s lying on the ocean floor While most other animals, including fish, hunt their prey by means of their eyesight, sharks hunt essentially by smell. They have a very acute sense of smell - and can sense the presence of food long before they can see it. Q33 Q34
