问题补充：
---Did you watch the programme I’m a singer on Friday night? It was wonderful.
---I wish I had, but I for the mid-term examination.
A. was preparing
B. prepared
C. had prepared
D. would prepare
答案：
(答案→)A. was preparing
B. prepared
C. had prepared
D. would prepare
解析：句意：--你看过周五晚的节目《我是歌手》吗？它是非常好的。--我希望我能去，但是我当时在准备期中考试。因为这是说的过去的事情，过去在做某事，故用过去进行时，故选A。一般过去式表示过去常常做某事；过去完成时是相对的时态，表示过去的过去；过去将来时表示过去将要做的事。故选A。
