GWD-31-Q28

Rock samples taken from the remains of an asteroid about twice the size of the 6-nuke-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 3.47billion 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

C为何不对？请各位大虾指教！！！谢谢！！！

date back to 是介词词组

选D么？

很遗憾~

A