He traveled to many mountain villages and saw many poor children out of school. This experience his life.
A. would change
B. had changed
C. was to change
D. was changing
网友回答
A. would change
B. had changed
(答案→)C. was to change
D. was changing
解析：be to do表示预定，命运，意为“注定要……”。本句意为“这个经历注定要改变他的生活”。A项表示过去将来，意志或倾向。