--Do you know what caused the accident? --- No, not yet. The matter .
A. is being looked into
B. was being looked into
C. looked into
D. is looked into
网友回答
(答案→)A. is being looked into
B. was being looked into
C. looked into
D. is looked into
解析：考查时态语态。因为回答是还没有知道，说明这件事情还在调查之中。所以用现在进行时。