OG13 CR22 B选项的解释看不懂，求指点

SharonZ0902

B This statement indicates that the undeveloped airstrip near Greentown might be a better way to alleviate flight delays at Greentown, but it tells us nothing about the effects that converting the Hevelia airstrip to a full-service airport would have were it to be carried out.

最后一个it 直接把我，撂倒了，不知道指代啥
感觉but后的句子好乱，求指点

WayneCH2012

it 指代this statement,也就是至题目的B选项,第二个it指代converting the Hevelia airstrip to a full-service airpot，意思就是 B选项这个陈述表明一个靠近G机场的未经开发的跑道可能是缓解G机场飞机延误的更好的办法（与在40英里外修建Hevelia跑道相比），但是这个陈述没有告诉我们任何把H跑道转变成全方位服务的机场后的结果.我觉得but后面的句子可能是but it tells us nothing about the effects that converting the Hevelia airstrip to a full-survice airport would have if it were carried out.

SharonZ0902

to be carried out
怎么解释？
不是were carried out啊
不定式到底是修饰谁的

franciszmy

were it to be carried out是 if it were to be carried out 的倒装  是个虚拟语气； were to是 is to的过去时，虚拟语气中is am 的过去时都用were

be to 是个固定搭配 表示将要 大致可以和will的意思相同