15, 16. (a) What restoration and refining work has been accomplished in modern times, and by whom?
١٥ ،‏ ١٦ ‏ (‏ أ )‏ أَيُّ عَمَلِ رَدٍّ وَتَمْحِيصٍ يَجْرِي فِي ٱلْأَزْمِنَةِ ٱلْعَصْرِيَّةِ ،‏ وَمَنْ يَقُومُ بِهِ ؟‏