When the old man to walk back to his house the sun itself behind the mountain.A. started

问题补充：

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

答案：

(答案→)A. started; had already hidden

B. had started ;had already hidden

C. had started; was hiding

D. was starting; hid

解析：考查时态。句意：当老人开始走回家的时候，太阳已经下山了。说明太阳下山是在老人回家之前。老人回家用过去时，太阳下山用过去完成时。这两句的时态要一致，故A正确。