aLL the president's men ______ one of the important books for historiand who study the watergate scandal.

问题描述:

aLL the president's men ______ one of the important books for historiand who study the watergate scandal.
答案是remains.请问为什么要加s?

All the President's Men 是一本书,是讲尼克森水门事件的书.
这句子的意思是:
All the President's Men还是对学习水门事件的历史学家来说是一本重要的书.
因为All the President's Men是一本书,所以他是单数,所以要加s.