Exam LSAT Topic 3 Question 77 Discussion

Most people think it's fine to be ''busy as a beaver.'' Little do they know. Beavers maywork hard, but often they don't get much done.Beavers are supposed to be great tree cutters. It is true that a beaver can gnaw through atree very quickly. (A six-inch birch takes about ten minutes.) But then what? Often thebeaver does not make use of the tree. One expert says that beavers waste one out of everyfive trees they cut.For one thing, they do not choose their trees wisely. One bunch of beavers cut down acottonwood tree more than one hundred feet tall. Then they found that they could notmove it.In thick woods a tree sometimes won't fall down. It gets stuck in the other trees. Of course,doesn't think to cut down the trees that are in the way. So a good tree goes to waste.Some people think that beavers can make a tree fall the way they want it to. Not true. (Infact, a beaver sometimes gets pinned under a falling tree.) When beavers cut a tree near astream, it usually falls into the water. But they do not plan it that way. The fact is thatmost trees lean toward the water to start with.Now what about dam building? Most beaver dams are wonders of engineering. The bestones are strongly built of trees, stones, and mud. They are wide at the bottom and narrowat the top.Beavers think nothing of building a dam more than two hundred feet long. One dam, inMontana, was more than two thousand feet long. The largest one ever seen was in NewHampshire. It stretched four thousand feet. It made a lake large enough to hold fortybeaver homes.So beavers do build good dams. But they don't always build them in the right places. Theyjust don't plan. They will build a dam across the widest part of the stream. They don't tryto find a place where the stream is narrow. So a lot of their hard work is wasted.Beavers should learn that it's not enough to be busy. You have to know what you're doing,too. For example, there was one Oregon beaver that really was a worker. It decided to fix aleak in a man-made dam. After five days of work it gave up. The leak it was trying toblock was the lock that boats go through.What is the main idea of this passage?