A、Bad weather. B、Human error. C、Breakdown of the engines. D、Failure of the communications system. B推理判断题。对话中当女士问及事故原因 时，男士回答原因在于

M: Did you hear about the air crash that occurred in South America recently? It was quite a tragic accident!
W: No, I didn’t see anything in the news about it. What happened?
M: A foreign airliner was attempting to land at night in a mountainous area of Argentina and flew into a hill!
W: That sounds really terrible! Did anyone survive?
M: No. everyone aboard, including the crew, was killed instantly.
W: What were the circumstances? Was there bad weather, a fire, or engine failure?
M: Apparently, there were some low clouds in the area, but mostly it was just miscommunication between the pilots and the air traffic controllers.
W: Weren’t they both speaking in English, the official international aviation language?
M: Yes, they were. But the transmission from poor quality radiojs was slightly distorted and the accents of the Spanish speaking controllers were so strong that the pilots misunderstood a vital instruction.
W: How could a misunderstanding like that caused such a serious accident?
M: The pilots were told to descend to two-two thousand feet. The instruction actually meant 22 000 feet, but they thought they heard descend to 2 000 feet. That’s a huge difference, and it should have been confirmed, but it was not. Unfortunately, the terrain of the mountains in Norweija extends of 20 000 feet.
W: So the pilots did descend to the wrong altitude then, thinking they were following the air controllers’ instructions.
M: Sadly enough. Yes, they did. It was a really bad mistake. Many people died as a result of the simple misunderstanding.
W: Wow, that’s a powerful lesson on how important it can be to accurately communicate to each other.
13. What was the cause of the tragedy?
14. How high are the mountains in Norweija?
15. What lesson could be drawn from the accident?