If this doctor, who lived one block away from there, would have come 20 minutes earlier, not have to wait until that siren he heard before coming from the ambulance, if he would have heard about it way before, he would have saved this child.
如果，这位住在一条街以外的医生 能早来20分钟， 而不是等听到救护车的警报声 才来， 如果他之前听到了， 他就能救了这个孩子。