It was true that he had just bought a lamb, he explained, but his lamb was black. Ashamed of having acted so rashly, Dimitri apologized to Aleko for having accused him. While they were talking it began to rain and Dimitri stayed in Aleko's house until the rain stopped.

　　13. It was true that he had just bought a lamb, he explained, but his lamb was black.

　　不错，他的确刚买了一只羔羊，阿列科解释说，但他的羔羊是黑色的。

　　语言点:句子结构分析:he explained为插入语。本句中含有主语从句，it是形式主语，that引导的部分是真正的主语，即“他刚买一只羔羊这件事是真的”。

　　14. Ashamed of having acted so rashly, Dimitri apologized to Aleko for having accused him.

　　迪米特里为自己的鲁莽而感到不好意思，向阿列科道了歉，说是错怪了他。

　　语言点:句子结构分析:ashamed of having acted为过去分词短语作原因状语，其中又含有一个现在分词的完成时结构，交代“感到不好意思”的原因，其省去的潜在主语是Dimitri,因为后半句也出现了Dimitri,所以为了避免重复，可以省略。

　　15. While they were talking it began to rain and Dimitri stayed in Aleko's house until the rain stopped.

　　就在他俩说话的时候，天下起了雨，迪米特里便呆在阿列科家里避雨，一直等到雨停为止。

　　语言点:句子结构分析:句中的and连接两个并列的分句，在前一个分句中，while引导时间状语从句，说明在同一时间段内同时发生的两件事情;在后一个分句中，until也引导时间状语从句，连接先后发生的两个动作。