What's on the desk?There is ___pencil on it?

问题描述:

What's on the desk?There is ___pencil on it?
为什么填a

因为pencil是个可数名词,如果你这个搞不清楚,可以看be动词,is修饰单数的,而are修饰复数的,而这里是is,所以填a.