If there(be)__________ no oxygen on earth,life as we know it(exist,not)________

were
wouldn't exist
虚拟语气的考察.
就填 我这个.
地球上肯定 有氧气,
没有氧气肯定 是虚拟.
绝对是对的!Tom's hobby is collecting stamps from all over the world.If he （travel)____ to a new country,he（spend,always)________time looking for new stamps.travelswill always spend此题不是虚拟，How old(live, human beings)______to be if all diseases in the world (be)______completely eradicated?were human beings were虚拟语气。楼主，一体一帖。不是（live,human beings)么？ live 呢？would human being live没看到 live