215. (30128-!-item-!-188;#058&004836) (GWD-31-Q28)
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 句子结构:Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurs have been dated at 3.47 billion years old and thus are evidence of the earliest known asteroid impact on Earth.
请教下~Date at/to be用法的区别 |