Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurs has been dated to be 3.47 billion years old and thus is evidence of the earliest known asteroid impact on Earth.
(A) has been dated to be 3.47 billion years old and thus is
(B)has been dated at 3.47 billion years old and thus
(C)have been dated to be 3,47 billion years old and thus are
(D) have been dated as being 3,47 billion years old and thus
(E)have been dated at 3.47 billion years old and thus are
题目分析：主语是samples，是个复数，不能用has，干掉A和B。用and连接两个东西，后面用are前面用being显然不合适，干掉C。C和E就是一个小词，一个to be 一个as，to be强调后面的动作和前面的date这个动词有前后关系，as就是把date的内容补充说明完整，强调的显然是后面的语义，选E
