He ______ at the meeting, but his heart attack prevented him.

He ______ at the meeting, but his heart attack prevented him.

A.will speak

B.is going to speak

C.had to speak

D.was going to speak

答案及解析： D

解析：

由题意“他本来打算在会上发言，但……”可知应该用过去将来时，只有D是过去将来时的形式。