【单选题】A man who had purple ears came to the attention of a human geneticist. The human geneticist did a pedigree analysis and made the following observations: In this family, purple ears proved to be an inh...
【简答题】听下面一段材料, 回答第1至3题. 1. How was the land when the man's father bought it? A. It had very few animals on it. B. It had been opened up by others. C. It was full of many native animals. 2. How long did it t...