根据短文，选择合适的单词填入短文下面的横线中。

    It's very hot. An old man is on the chair. A fly comes and sits on the end of the man's nose. The old man has a monkey. He chases the fly. The fly comes back again and sits on the old man's again. The monkey chases it away again and again. This happens five or six times. The monkey is very angry. He jumps up, runs to the and picks up a large stone.

    When the fly sits on the old man's nose again, the monkey hits it hard with the. He kills the fly and the old man's nose.