When the old man _______ to walk back to his house, the sun ________ itself behind the mountain.
A. started; had already hidden B. had started; had already hidden
C. had started; was hiding D. was starting; hid
When the old man _______ to walk back to his house, the sun ________ itself behind the mountain.
A. started; had already hidden B. had started; had already hidden
C. had started; was hiding D. was starting; hid
A老人开始跑回家与太阳落山两个动作都发生在过去，而后者又发生在前者之前，故前者用一般过去时，后者用过去完成时。