Answer:
The two pyramids are quite similar from the age of 25 and higher, as might be expected. The biggest change is the rapid drop-off of people under the age of 10. Children aged 0-4 went from almost 16% of the total population in 1970 to less than 10% in 1980. This data clearly indicates that the one-child policy caused a dramatic change in birth rates between 1970 and 1980.
Explanation: Exact answer from tutorial.