wouldhavebeen是表示与过去发生的情况相反么?下面这段话中的wouldhavebeen我感觉应该是假设的意思啊Nowlet'slookatanothertheory,uh,analternativetothehuntingtheory,theclimatechangetheory.Ataround11,500B.C.

Question

would have been是表示与过去发生的情况相反么?下面这段话中的would have been我感觉应该是假设的意思啊
Now let's look at another theory,uh,an alternative to the hunting theory,the climate change theory.At around 11,500 B.C.E.,the world was coming out of an Ice Age .And with that came increased seasonality,that is,the summers became warmer,and the winters actually became colder.These extreme shifts would have put a lot of stress on the bodies of animals that were used to a more moderate range of temperatures.

Answer 1

这是过去将来完成时.
过去将来完成时表示在过去将来某一时间以前发生的动作,并往往会对过去将来某一时间产生影响.
除了用于虚拟语气,表示与过去情况相反以外,也可以表示推测.
对过去的推测 用would do
如果对 过去某个时间以前的 推测 就用 would have done.
如she would have told him something by then.届时 ,她就可能已经告诉他了.