单选题 Banks are not ordinarily prepared to pay out all accounts ; they rely on depositors(储户) not to demand payment all at the same time. If depositors should come to fear that a bank is not safe, that it cannot pay off all its depositors, then that fear might cause all the depositors to appear on the same day. If they did, the bank could not pay all accounts. However, if they did not all appear at once, then there would always be enough money to pay those who wanted their money when they wanted it. Mrs. Elsie Vaught has told us of a terrifying bank run that she experienced. One day in December of 1925 several banks failed to open in a city where Mrs. Vaught lived. The other banks expected a run the next day, and so the officers of the bank in which Mrs. Vaught worked as a teller had enough money on hand to pay off their depositors. The officers simply told the tellers to pay on demand. The next morning a crowd gathered in the bank and on the sidewalk outside. The length of the line made many think that the bank could not possibly pay off everyone, People began to push and then to fight for places near the tellers' windows. The power of the panic atmosphere was such that two tellers, though they knew that the bank was quite all right and could pay all depositors, drew their own money from the bank. Mrs. Vaught says that she had difficulty keeping herself from doing the same.

单选题 A bank run happens when ______.

单选题 The main cause of a bank run is ______.

单选题 Which of the following did Mrs. Vaught say?

单选题 According to the passage, the actions of the depositors of Mrs. Vaught's bank were affected mainly by the ______.