He insisted that hesuffer from heart trouble, but I didn’t think so.
A. should suffer
B. has suffered
C. suffers
D. was suffering
网友回答
A. should suffer
B. has suffered
C. suffers
(答案→)D. was suffering
解析：考查时态。句意：他坚称他正患心脏病，但是我不这么认为。可知前文描述的是过去正在发生的事情，故用过去进行时态。选D。