When he went outside half an hour later, he was astonished to find the little black lamb was almost white. Its wool, which had been dyed black, had been washed clean by the rain!

　　16. When he went outside half an hour later, he was astonished to find the little black lamb was almost white.

　　半小时后，当他从屋里出来时，他惊奇地发现小黑羔羊全身几乎都变成白色。

　　语言点:句子结构分析:when引导时间状语从句。主句中的that引导宾语从句，交代find的内容。

　　17. Its wool, which had been dyed black, had been washed clean by the rain!

　　原来羊毛上染的黑色被雨水冲掉了!

　　语言点:句子结构分析:which引导非限制性定语从句。Had been washed是过去完成时的被动语态，强调颜料完全被冲刷掉了。