OG12-73的完成时态，大概弄明白了，请nn指点

尘埃透明

73. Combining enormous physical strength with higher
intelligence, the Neanderthals appear as equipped for
facing any obstacle the environment could put in their
path, but their relatively sudden disappearance during
the Paleolithic era indicates that an inability to adapt
to some environmental change led to their extinction.
(A) appear as equipped for facing any obstacle the
environment could put in their path,
(B) appear to have been equipped to face any
obstacle the environment could put in their path,
(C) appear as equipped to face any obstacle the
environment could put in their paths,
(D) appeared as equipped to face any obstacle the
environment could put in their paths,
(E) appeared to have been equipped for facing any
obstacle the environment could put in their path
我和很多人一样纠结于为什么正确答案B要用完成时态
搜到这么一段在动词seem，appear  等之后的动词不定式的完成时态。如果动词
   
   不定式的完成时态与动词seem，appear 等连用，表示不定式的动作或状
   
   态在说话之前已经发生，而这种动作或状态在说话时已经知道。
   
   a．He appears to have made a small mistake．
   
   （=It appears to have made a small mistake．）
大概能够解释这个时态了，Neanderthals be  equipped在先，appear在后（因为有了才能显示出来），并且be equipped是已知的情况，所以应该这个时态来表达。
不知道自己理解的是否正确，求指点！