The 115m Christmas Bird Count is officially underway. The count is an annual investigation of local and migratory(迁徙的)birds and it's organized by the National Audubon Society. From  December 14 to January 5, volunteers will gather in more than 2,000 locations in North, Central and South America to count the birds in their area.
Each count takes place in a circle about 24 kilometers wide. The volunteers follow specific routes within the circle and record the number of individual birds and the different species they see there in a single day. The results are sent to the National Audubon Society and later published on Audubon's Christmas Bird Count website. The data collected during the bird count is a key source Of information for ornithologists, scientists who study birds.
This information is used to develop conservation programs to protect bird habitats and the environment /n general. Data from the bird count was also used to determine that three species-the Western screech owl, the rusty blackbird and the Newfoundland red crossbill - should be added to Canada's list of species at risk.
The annual bird count was created to protest another Christmas tradition at the very beginning .in the United States in the 19th century, people would often hold "side hunts" on Christmas Day.
Teams of hunters would compete to see who could kill the most birds or other animals that day. In  December 1900, Frank Chapman, an American ornithologist, suggested that instead of hunting birds, people should count them.
Twenty-seven people in 25 locations joined in the first Christmas bird count Last year, more than 70,000 volunteers took part. This year, counts are scheduled to take place in 17 countries, ranging from the Arctic to the Antarctic, with most located in Canada and the United States .instead of taking place only on Christmas day, counts are now held on different days for different areas.
How long will the 115th Christmas Bird Count last?

A．About 3 weeks.	B．A single day.
C．About a month.	D．About 2 weeks.

What can we know about the Christmas Bird Count from the passage?

A．It was organized monthly by the National Audubon Society.

B．It was launched by Frank Chapman, a Canadian ornithologist.

C．Its results can be seen on Audubon's Christmas Bird Count website.

D．Only 25 people in 27 locations took part in the first Christmas Bird Count.

Why was the Christmas Bird Count established at first?
A. To help the scientists who study birds carry out their study.
B To protest the Christmas tradition "side hunts" on Christmas Day.
C. To determine whether the rusty blackbirds are endangered animals.
D To protect bird habitats and the environment from being destroyed
What is mainly talked about in Paragraph 5?

A．The brief introduction to the Christmas Bird Count

B．The origin of the Christmas Bird Count.

C．The purpose of the Christmas Bird Count.

D．The rapid development of the Christmas Bird Count.