without the sun ,life as we know it_ A would not exist B would not have existed答案A为什莫不是B
问题描述：
without the sun ,life as we know it_ A would not exist B would not have existed答案A为什莫不是B
without the sun ,life as we know it_ A would not exist B would not have existed答案A为什莫不是B
答
A和B都是虚拟语气,因为没有太阳是虚拟的条件,B是虚拟过去时.A是虚拟现在时.选A是因为without sun 是对现在时态的虚拟.如果用虚拟过去时,应该说 If we hadn't had the sun,life as we know it would not have existed.