正确答案为：
How many ruler is there in the pencil box?文具盒里有多少个尺子?为什么不是how many rulers in the pencilbox因为题目是：There is a ruler in the pencil box.
提问就要有 Is there.

如果题目是：A ruler in the pencil box.
提问才是：How many rulers are in the pencil box最终答案应该是how many rulers are there in the pencilbox 吧可以，也可以是：How many ruler is there in the pencil box?