Question: What is the production code for the episode that had 18.07 million viewers? 
SQL: SELECT "Production code" FROM "1-26198709-1" WHERE "U.S. viewers (million)" = '18.07';

Question: What is the weeks rank for the episode with the production code 1ALF05? 
SQL: SELECT MAX("Rank (week)") FROM "1-26198709-1" WHERE "Production code" = '1ALF05';

Question: How many air dates does the episode with 15.50 million viewers have? 
SQL: SELECT COUNT("Original air date") FROM "1-26198709-1" WHERE "U.S. viewers (million)" = '15.50';

Question: Who wrote the episode with 18.07 million viewers? 
SQL: SELECT "Written by" FROM "1-26198709-1" WHERE "U.S. viewers (million)" = '18.07';