Unfortunately,_______the old man______his dog was safe from the fire.A.both...andB.neither...norC.either...orD.not only...but also为什么说明这四个选项的用法

问题描述:

Unfortunately,_______the old man______his dog was safe from the fire.
A.both...and
B.neither...nor
C.either...or
D.not only...but also
为什么
说明这四个选项的用法