听力原文： You have read a great deal about the behavioral pat terns of various species in

your textbook.

During this time, many students have asked me how these studies have been conducted. So I'm going to spend this class period talking about how I am conducting my re search project. In this project, my research assistants and I trace the migration pattern of the grizzly bears by using computer technology.

I decided to research the grizzly bears because they are gradually disappearing around forests in the Yosemite area. One distinct characteristic of this bear is its hibernating spots, however, the grizzly bears are disappearing. We hope to discover why they are vanishing, so we can prevent them from becoming extinct.

My research assistants are helping me implant computer chips, no bigger than a small stone, on the bears. Why computer chips, you might ask？ Well, previous research projects used to imprint the bears with bits of marked wire. This process created an unusually large amount of work for the researchers because, in order to retrieve the information later, they had to find the bears. With computer chips, we can track the course of the grizzly bears without interfering in their travels.

We can do this by placing a series of wireless antennas along the possible routes of the bear. The implanted computer chips allow us to easily locate them because their location is transmitted whenever they pass the antennas. This allows us to monitor many bears and track their progress with less effort.

We already know that a species of the coyote may present problems for the bear. We are still unclear, though, on how the coyote may contribute to their decline. Hopefully, these computer chips will help us find the answer.

How do the speaker and his assistants trace the grizzly bear？

A．By tracing them.

B．By using computer system.

C．By using computer technology.

D．By studying science papers.