问题
选择题
They received a number of _____ from customers about the lack of parking facilities.
A．complains
B．complaints
C．complainer
D．complainers
答案
B
句意：他们收到了许多来自顾客的抱怨关于缺乏停车设备。名词，抱怨complaint，题中a number of 修饰可数名词复数，所以选B。