以下是引用apple0000006在2008-6-7 16:08:00的发言:Astronomers at the Palomar Observatory have discovered a distant supernova explosion, one that they believe is a type previously unknown to science. A. that they believe is B. that they believe it to be C. they believe that it is of D. they believe that is E. they believe to be of 从逻辑意思来解决: 注意believe后面的宾补是 type , 而distant supernova explosion本身不可能是一个type只可能是type的一种, 所以要用到词组: of a type, 可以把 A排除, 虽然从语法上没错 B one that they believe it to be 既然已经用定从修饰one 了, 则belive后面不需要在出现代词it , 冗余 C明显的罗嗦, it 与 one 重复 D believe that 宾从后面没有主语 E best one( 定从先行词坐宾语,省略that) they believe to be of a type |