Sperm whales（抹香鲸）live in every ocean on the earth. Their large heads help them stand out from other whales. 【小题1】

They have the biggest brains on Earth. Human brains weigh about 1.4 kilograms. However, a sperm whale’s brain can weigh up to 9 kilograms! They are clever sea animals. Sperm whales are good at diving（潜水）. These huge animals can get to around 2,000 meters deep and can go for over 60 minutes between breaths. 【小题2】 They make special high sounds to send information to one another from hundreds of kilometers away. The sounds are even louder than those made by planes. What’s more, each whale makes its own sound. 【小题3】

They produce Ambergris（龙涎香）that is worth as much as gold. 【小题4】Ambergris is thought to protect the whale from the sharp things that it eats. Sperm whales release（释放）ambergris into the sea as a sweet-smelling, egg-shaped ball. Because ambergris is often used in fine perfumes（香料）but so hard to get, so a kilogram of it can sell for up to $50,000.   【小题5】 Sperm whales are amazing animals on Earth.

根据材料内容，从下面五个选项中选出能填入文中空缺处的最佳选项，使文章意思通顺、内容完整。

A．Scientists believe this makes it easy for them to know one another.

B．They are the loudest animals alive.

C．Here are some fun facts about them.

D．This makes them one of the most valuable things on Earth!

E．It is an amazing thing that comes from the stomach of a sperm whale.