有读者问这样一句话：
A lot of research work has been carried out in recent years, but much still has to be learned about the land lying under the ice.
learned about在这里应作为一个固定的短语动词去理解，还是应把about引导的短语作为一个定语修饰much?
可以将learn about看作一短语动词（参见Longman Dictionary of Phrasal Verbs ）。about在此意谓“关于”，learn about在此可译作“了解”。
