When you look for a job it's not your book knowled

问题补充：

When you look for a job,its not your book knowledge but your experience------matters more.AwhetheBwhich Cwhat

答案：

1）it is that 这是一个固定的强调式句型

2）句子中不缺任何成分,即横线处你不加其它的词句子仍成立.