If human beings had been a bit less greedy and cruel,more birds and animals______dying out.a.ought to avoid b.could have been avoided c.should have avoided d.would have a dvoided为什么是D呢?

1. If human beings had been a bit less greedy and cruel, more birds and animals __d___ dying out. human beings are human beings human ,human beings 区别 If there are no trees,human beings and animals will die._______ _______ ,human beings and animals will die. human being还是human beings? human beings humans区别? human beings是什么意思? humans=human beings? human beings to program If human beings had been a bit less greedy and cruel,more birds and animals______dying out.a.ought to avoid b.could have been avoided c.should have avoided d.would have a dvoided为什么是D呢? human beings与human being的区别 THE HUMAN USE OF HUMAN BEINGS怎么样 being VS human beings 区别! Care More for Human Beings? It's high time,if we human beings are to survive ,we_____(承诺)to do sth to improve the environment 3. If human beings could not （） with one another, each person would have to learn everything for natural goodness of human beings什么意思 Water,Earth and Human Beings的意思