阅读下面短文，掌握其大意，然后从1~7 各题所给的三个或四个选项中，选出最佳选项。

There was once a farmer who lived near a road. It was not a1road, but from time to time, cars passed the farm.

Near the farm gate, there was a large 2 in the road. This hole was always full of water.

The drivers of the cars that passed by could not 3 how deep the hole was. They thought it was probably shallow (浅的). Then when they drove into the hole, they could not drive4because it was very deep.

The farmer did not spend much time5on his farm. He spent most of time watching the hole. When a car drove into it, he pulled the car out with his tractor (拖拉机) and demanded a lot of6 for doing this.

One day, a driver of a car said to him: “You must make a lot of money by pulling cars out of this hole7.”

“Oh, no,” the farmer said. “I don't pull cars out of the hole at night. At night I fill the hole with water.”