标题: 请教og12-14 和73的平行结构时态问题 [打印本页] 作者: 红尘道士 时间: 2009-12-25 21:49 标题: 请教og12-14 和73的平行结构时态问题 og12-14:Sunpots,vortices of gas associated with strong electromagnetic activity, are visible as dark spots on the surface of the Sun buthave never been sighted on the Sun's poles or equator.
这里的but前后时态可以不一致
og12－73：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.
og D中的解释： Present-tense appear is needed to parallel Present-tense indicates作者: rose86511 时间: 2010-1-24 10:55
你上面说的这道题，but前面说的是：太阳黑子，……，被人们观测到是太阳表面的黑点。这是一个科学事实，我们知道，科学事实是要用一般现在时的。