english: I should like to finish by comparing some of the questions we set out to answer with some of the problems today, twenty years later.
non_english: ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡