Using coordination:What we want to get are two vans. What we wan

Using coordination:
What we want to get are two vans. What we want to get is a tractor.
【正确答案】：What we want to get are two vans and a tractor.
【题目解析】：What引导的主语从句，谓语动词要视表语而定：表语是单数名词时，谓语动词用单数，相反，则用复数。