英语句式解析："had it not been for the diamonds"前面是否需要连词?it指代什么?原句：The reasearch has been underway in southern Africa for four years now,and it problably wouldn't have happened there had it not been for the diamonds.

1 记住，if it had not been for the diamonds, -- - - - 是正常语序。但如果变成了倒装句语序，if 就不存在了。
2 if it were not for - - - - /// if it had not been for -- - -（这个从句部分） 里面的 it 指代 主句部分所说的事情。
Had it not been for your help, I would have had to wait five more days ----------这里的it指代 I would have had to wait five more days 这件事。

不需要连词，是虚拟语气语法

不用连词,这半句原本用if连接的从句,但是改为了倒装句式,连词就省略掉了.it指的是前半句说的那个research.

had it not been for the diamonds=if hit had not been for the diamonds【假如不是钻石的原因】
it需根据语境断定指代物。