In this section, you will hear one passage. At the end of the passage, you will hear four questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).A、About 245 million years ago.
B、About 66 million years ago.
C、About 60 million years ago.
D、About 6 million years ago.