Sixty-five million years ago, according to some scientists, an asteroid bigger than Mount Everest slammed into North American, which, causing plant and animal extinctions, marks the end of the geologic era known as the Cretaceous Period.
B. which caused the plant and animal extinctions and marks
E. an event that caused the plant and animal extinctions that mark （正解）作者: rudder86 时间: 2010-11-8 21:11
首先，这里如果选B，那么which就近指代North American，从逻辑上来说是说不通的。
其次，B的意图其实是想用which指代 an asteroid bigger than Mount Everest slammed into North American这一句话，表达这一句话造成的影响。which是不能指代一句话的，所以要用E中的同位语a event来概括这句话。作者: banglixing 时间: 2010-11-9 06:50
B选项：
（1）如果按就近修饰原则，which 应该是修饰North American的，which make no sense.
（2）event 标志了白垩纪的结束，而不是North American（which指代的对象）作者: queenie924 时间: 2010-11-11 06:44
