were
这是虚拟语气的倒装形式,把if省略了.
正常顺序是：If it were left to me to decide,I would not hesitate to prefer the 1atter.
在虚拟语气的倒装句中,如果if 从句中含有were,had,或者should就可以省略if,把它们提前构成倒装.