具有社会行为的动物，群体内部往往形成一定的____  ，成员之间有明确的____ ，有的群体中还形成等级。

完形填空

    Mr. Smith lived in a big city. When he retired(退休), he bought a small 1in a village near the sea. He2it and hoped to live a quiet life in this house.

    But to his great surprise, many visitors came to see his house in summer holidays, for it was the most 3building in the village. From morning to night there were 4outside the house. They kept looking 5the rooms through the windows and many of them even went into Mr. Smith's garden. This was too much for Mr. Smith. He decided to ask the visitors to 6. So he put a notice (告示) on the window. The notice said, “If you want7it, come in and look round. Price: twenty dollars.” Mr. Smith was sure that the visitors could8coming, but he was wrong. More and more visitors came and Mr. Smith had to 9every day taking them around his house.“I came here to 10not to work as a guide,” he said angrily. In the end, he sold the house and moved away.