下列物态变化中，都是吸热的是 (       )

    O. Henry was a pen name of an American writer. He wrote short stories. His real name was William Sydney Porter. He was born in North Carolina in 1862. As a young boy he lived an exciting life. He did not go to school for very long, but he tried to teach himself everything he needed to know. When he was about 20 years old, O. Henry went to Texas. There he tried different jobs. He first worked on a newspaper, and then had a job in a bank. When some money was lost from the bank, others believed O. Henry took it. So people sent him to prison﹡. He stayed in prison for three years. There he learned to write short stories. After he got out of prison, he went to New York and went on writing. He wrote mostly about New York and the life of the poor there. People liked his stories, because they always finished with a sudden change at the end, to the reader's surprise.

“犁”是古代中国农业生产的重要工具，下列关于它的表述错误的是（  ）