单项选择题
Questions 21 to 23 are based on the following news. At the end of the news item, you will be given 15 seconds to answer the questions. Now, listen to the news.
How did they survive during those three months（）
A．On supplies they brought with them.
B．On supplies sent to them by rescue teams.
C．On supplies left at the military base.
D．Not mentioned in the passage.