A professor told his students to go into the city slums(贫民窟) to study the life of 200 boys.He asked them to (41) reports

A professor told his students to go into the city slums(贫民窟) to study the life of 200 boys.He asked them to (41) reports(报告) about each boy’s future.Most of the students wrote,“He doesn’t have any hope.”
Twenty-five years (42) ,another professor read about the earlier reports.He told his students to (43) what had happened to the boys.They tried very hard and found that 176 of the boys had become successful (44) doctors,teachers and scientists.
The professor was very (45) and decided to study it further.Luckily,all the men were living near the same city and he was able to visit and ask each one,“What made you (46) ” They all answered,“There was a good teacher.”
The teacher was (47) living there,so the professor found her and asked the old lady (48) she had pulled those boys out of the slum,and changed them into successful people.
The teacher’s (49) began to shine and said with a sweet smile,“It’s really very easy.I (50) those boys.I’m proud of them.”