问题
单项选择题
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
答案
参考答案：A
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。