问题
选择题
The number of people invited ____ fifty, but a number of them ____ absent for different reasons.
A．were , was
B．was , was
C．was , were
D．were , were
答案
C
题目分析：考查主谓一致。固定词组the number of…指“…的数量”；该短语做句子的主语，谓语动词用单数的形式；a number of…指“许多”修饰可数名词复数形式，做主语时候，谓语动词用复数形式。句意：被邀请的人的数字是50，但是很多人都因为各种原因没有到场，故C正确。
点评：本题的主谓一致遵循了语义一致的原则，也就是短语所表示的是单数还是复数形式，根据意思来决定具体的单复数形式。