单选题 Of the 9500 drivers ______ since the beginning of the year, 23% were found ______ in road knowledge.
A．tested lacking
B．having been tested to lack
C．tested lacked
D．to have been tested lack

【正确答案】 A
【答案解析】[解析] tested为过去分词，用做后置定语；第二空driver与lack之间为主谓关系，find sb doing/done。故选A。