M: Wait till you hear what the project is...She's working with the buffalo population. The herds have been increasing in size lately, which is good in theory...

　　W: Yeah...but I thought they were in danger of becoming extinct.

　　M: Well, apparently, because of all the winter tourists, paths are created in the snow. More buffalo are surviving the harsh winters because the paths make it easier for the buffalo to move around and find food. But it turns out that some of the herds are infected with a bacteria.

　　W: Oh yeah, I heard about that. Bru—

　　M: Brucella abortus

　　W: Right, It's been around for quite a while.

　　M: Yes it has. And because the buffalo population is increasing, they've been roaming more than usual, and the disease has begun to spread to the cattle ranches that border toe park.

　　W: That's bad news! Isn't that the disease that causes animals to abort their young?

　　M: Yes, and it's caused a lot of controversy. Some of the ranchers even want to destroy the buffalo herds.

　　W: That's awful! Have they made much progress with the research?

　　M: So far, they've been collecting tissue samples from dead buffalo to see if the bacteria's present.

　　W: I'd really be interested in working on this. You know I've been researching dise-　ased animal populations...

　　M: That's why I thought of you...I took the liberty of mentioning your name to my friend. She's hoping you'll be able to spend the whole summer out there.

　　W: Well, I was going to work on my thesis a lot in July, but I'm sure my adviser wouldn't want me to pass up this opportunity.

　　Questions 19 to 21 are based on the conversation you have just heard.

　　Q19. What did the professor want to talk to Ann about?

　　Q20. According to the professor, why is the buffalo population increasing?

　　Q21. Why does the professor think Ann would be interested in going to Yellowstone?

　　Conversation two

　　W: Hmm, hi.

　　M: Hi, I’m going door to door tonight to tell people about the Student Action Union. Do you have a few minutes?

　　W: Sure. You know, I think I read something in the newspaper last week.

　　M: Yeah, there was an article about us since the last issue. See, we are trying to protect and preserve some of the open spaces on campus.

　　W: That’s right. You are the group that’s opposing the extension of the parking lot next to Darwin Hall, right?

　　M: That’s us. We just feel it is important to save some of the natural beauty of the campus. Some of those trees are hundreds of years old.

　　W: It’s a pretty spot. My friends and I had picnics over there by the stream.

　　M: Then you understand how we feel. We are going to organize a protest on Thursday afternoon to get the administration to reconsider the parking lot plan.

　　W: Well, I have a class on Thursday afternoon.

　　M: But maybe you could sign this appeal letter. We are going to submit it to the administration to demonstrate how the students feel about this.

　　W: Sure, let me get a pen and I will sign it.

　　M: I have a pen right here. And let me leave you this booklet about the Student Action Union. Maybe you could come to some of our meetings. We get together once a month.

　　W: Yeah,, I'd like to know more about your group. Let me know when the next meeting is and I will try to be there.