a series...is/are

【问】 A series of debates between the lecturers were scheduled for the next weekend.(攻读硕士学位研究生入学考试英语试题，81A)

答案规定(C)为错误(应改为was)。a series of+复数名词(如a series of meetings/lec-tures/experiments/discoveries/rooms/mistakes)表达的是复数概念，为什么谓语动词要用单数?

【答】 在英语里，主语与谓语动词的一致关系存在着三个原则：语法一致原则，概念一致原则和接近原则。有时候这三个原则是会发生矛盾的。如果遵循语法一致原则，就会违背概念一致原则，或者相反。例如，five years(weeks，months) is...ten dollars is，the audience are，anumber of...are，a lot of...are便是遵循概念一致原则而违背语法一致原则的例子。而many a man is，a series of Ns is，则是遵循语法一致原则而违背概念一致原则的例子。我们英语学习者只能逐个记忆，而不能单纯依靠推理。但是要记住，规定语法学家以及各类标准英语考试的测试专家往往趋向于语法一致的原则。

下面的英语试题要求遵守语法一致原则：

1. At last，late in the afternoon，a long line of flags and colored umbrellas were seenmoving toward the gate of the palace. (TOEFL 教程)

2. A series of lectures are to be given to mark the centennial anniversary of the foundingof the school.

3. That set of four records，offered for a limited time only，are available exclusivelyin the stores mentioned. (TOEFL，74.9)

4. The kind of books an author writes depend on the kind of man he is.

5. A large collection of contemporary photographs，including some taken by Henry，areon display at the museum. (TOEFL，72.6;74.11)

6. This group，among whom are Jean and Eddie，certainly were the life of the party.(TOEFL，70.3)