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、Central plains of the middle reaches of the Yellow River.
B、High land in northern China.
C、Central plains of the lower reaches of the Yellow River.
D、Lower land in northern China.