Studies have shown, for example, that two drugs are about equally effective in treating macular degeneration, an eye disease.
出自-2015年12月阅读原文
柯林斯高阶英汉双解学习词典释义
VERB
恶化;变糟;衰退;堕落
If you say that someone or something degenerates, you mean that they become worse in some way, for example weaker, lower in quality, or more dangerous.