题目

An old skillful carpenter was ready to retire. He told his boss his plans ___________. His boss was sorry to see his worker ___________. He asked if _________ build him just one more house. The carpenter said yes, but he was not really interested. He used poor materials and didn’t work as _________ as before._________ the carpenter finished his work, his boss came to see the new house. He handed the _________ key to the carpenter. “This is your house” he said, “my gift to you.”_________ pity! If he had only known he was building his own house, he would have done it all so differently认一认。 ∠1是（    ）角；∠2是（    ）角；∠3是（    ）角；∠4是（    ）角；∠5是（    ）角；∠6是（    ）角；∠7是（    ）角；∠8是（    ）角。