爱华网听力是四级考试中的重要题型，考生对这部分的复习一定不能松懈，考生可以充分利用暑期时间坚持练习听力，下面是一篇英语四级听力练习，快来练练吧。
The future has arrived at a dairy farm about in an hour by car from Washington D.C. A robot is milking cows. It is milking time at Woodbourne Creamery in Mt. Airy, Maryland. The cows are standing in line for a turn at the robot.
John Fendrick is the owner of the farm. He inspects the progress of the animals by looking at a computer screen. That is all he has to do.
"The door of the milk opens up, they walk in, they get milked. The door opens up, they walk out."
John Fendrick checks the progress on the screen.
The robot does all the work. It uses a laser to find each teat -- the place on the cow where the milk comes out. The robot then cleans the teat and connects a milking tube to it.
The robot also tests the milk for possible contamination. If it finds a problem, it rejects the milk. When the amount of milk coming out of the cow slows, the machine knows to stop, and sends the cow on its way.
Milking robots are becoming popular among dairy farmers in the United States, Europe and Australia. John Fendrick says the robots have changed life on a dairy farm.
"You are giving the freedom back. So it allows me or the people work for me to actually do other things on the farm."
Most dairy farmers must milk their cows two times a day, early in the morning and late at night. The animals are milked everyday in good weather or bad. But Mr Fendrick's cows do not follow such schedule, they stay in the field until they want to be milked by the robot. Some of them come to be milked in the middle of the night.
Mr Fendrick doesn't even need to be there to watch his cows be milked. He can watch from his telephone. He can learn when each cow was milked and how much she produced. He can also learn if a cow has not been milked for a long time.
The cow milking robot is not low cost technology. Mr Fendrick paid more than $150,000 for it. But he notes, paying someone to milk the cows is also costly.
"In three years, I will have paid off the difference with this, and I don't have to be the person who's always on call to milk. The fact that we have a life, and our cows are able to function without us -- to us, it's well worth the money."
And he says that is a good thing. "I don't like to milk." With the robot, he can turn his attention to other things. He gets about 475 liters of milk a day, and he never has to touch a cow.
