The top-selling album (唱片), Songs of the Humpback Whale, was made public in 1970. This collection of nature recordings changed the way many people thought about whales, and it helped save thousands of whales' lives.

   The album might never have been made without a sound engineer named Frank Watlington. In the 1960s, Watlington was making underwater recordings when he noticed some strange, deep sounds. He realized they were coming from whales. Watlington played the recordings for a pair of scientists named Roger and Katy Payne. When they listened, they fell in love with these beautiful voices at once.

   Katy Payne studied music as well as animals, and she was greatly surprised by how the whales communicated using sounds like an opera (歌剧) singer. She also noticed another interesting fact: the sounds had clear patterns. According to scientists, an animal sound with a repeating pattern is called a song. Some scientists even compared these singing animals to musicians.

   The Paynes thought that other people should also hear the beauty of the whales' songs. So

Roger I made the recordings into an album. Al the time when the album came out, whales were often caught, killed and traded for money. Some kinds were even in danger of dying out. Most people had never thought that whales could communicate through songs. But after hearing the album, they began to think differently.

   The album led people to take action to save whales. Musicians began using whale songs in their music, and whales were included in movies and television shows. In 1982, a ban to stop deep-sea whaling was made. Before it, in the 1950s and 1960s, more than fifty thousand whales per year were killed. After it, the number went down below two thousand.

   It might seem impossible that just one album could help save the lives of so many whales. But this album told people secrets about whales that had long been hidden under the sea. It allowed whales to finally share their songs with the human world.

30. What is the purpose of the passage?

A．	To call on people to save whales.
B．	To tell how a good album was made.
C．	To show that whales are born singers.
D．	To introduce an album and its stories.

31. Who first found the special voices of the whales?

A．	A song recorder.
B．	An opera singer.
C．	A sound engineer.
D．	An animal scientist.

32. What fact about the whales surprised Katy Payne?

A．	They could talk with scientists.
B．	They could sing like an opera singer.
C．	They could repeat interesting sounds.
D．	They could communicate through songs.

33. Which is one of the values of the album?

A．	It successfully stopped deep-sea whaling.
B．	It helped people understand whales better.
C．	It made some music and movie stars popular,
D．	It encouraged musicians to work with scientists.