It flies through the night air.It is silent as it moves through trees and over grasses.It is a drone-a small plane that is operated remotely.Tonight,this drone is on a high-risk mission（任务）in South Africa：hunting poachers（偷猎者）.
Poaching has caused an environmental disaster.According to a study led by Colorado State University,nearly 100，000 African elephants were killed from 2011 to 2013.Rhino poaching has increased 9，000 percent since 2007 in South Africa alone,according to the World Wildlife Fund.
Now,conservationists are turning to drone technology to fight back.Air Shepherd is a program that flies drone missions in South Africa,Malawi,and Zimbabwe at night.If potential poachers are spotted,teams of park rangers（园林管理员）will go to the scene immediately.
Since the program began,Air Shepherd has seen a significant decrease in poaching in areas where its drones operate.And it is currently raising money to expand its operation,says John Pelersen,who is responsible for the program.
Petersen believes that drone technology can turn the tide in the war against poaching.There are certainly challenges though.For one,if poachers get word that drones are going around a particular area,the poachers may simply go elsewhere.Another challenge is training park rangers to use drones effectively.In addition,drones can be expensive to buy and can fly for only a few hours before running out of power.
Still,in the fight to save elephants and rhinos,drones have the potential to be an effective tool.
"These animals have been around for millions of years.They are a significant aspect of who we are and the environment we live in," says Petersen. "They could be extinct in the wild in Africa in 10 years...We can't let that happen."



What does Paragraph 2 indicate？ ______

A. The world's environment is getting worse.
B. Elephants are in danger of extinction.
C. Poaching has caught public attention.
D. Poaching is a very serious problem.

What do we know about Air Shepherd？ ______

A. It helps discover poachers.
B. It flies drones all day long.
C. It was started by John Petersen.
D. It makes money through drone service.

What challenge does drone technology face？ ______

A. Inadequate operators.
B. Inconvenience of charging.
C. Limited areas of coverage.
D. High expense of operator training.

What do Petersen's words show in the last paragraph？ ______

A. His worries about Africa.
B. His determination to fight poaching.
C. His belief in drone technology.
D. His pride in what he does.