英语高手! 是关于 英语语法的问题! 我纠结了!

题目

英语高手! 是关于 英语语法的问题! 我纠结了!
it‛s more convenient to communicate with your co-workers or boss
when you work in an office.
请问, 这里, it等于
to communicate with your co-workers or boss
when you work in an office.呢 还是 it 等于when you work in an office.
还是 it = 上句提过的 working in an office呢?
请高手 指点下!
其实 上去有个work in an office
那么 为什么不能是 it = working in an office呢？
即， working in an office is more convenient to communicate with your co-workers or boss
when you work in an office.

答案