Of the 9,500 drivers       since the beginning of the year, 23% were found lacking road 

knowledge.

A．test

B．testing

C．tested

D．were tested

“给定资料1”中指出“一种潜在的危机正在延伸”。请你结合“给定资料”，谈谈这种潜在危机是什么
要求：准确、全面，不超过200字。