标题: 请教OG-9 [打印本页] 作者: lingxia 时间: 2003-12-23 00:20 标题: 请教OG-9 9. 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 Choice E is best. The pronoun that in A and B should be deleted, since the pronoun one is sufficient to introduce the modifier and the sentence is more fluid without that.