With fall foliage replacing the blooming daffodils and mylar blankets sharing space with masks, the pandemic-delayed Boston Marathon returned Monday after a 30-month absence for a smaller, socially distanced race that ended in a very familiar way. Benson Kipruto and Diana Kipyogei completed a Kenyan sweep — the eighth since 2000 at the world's oldest and most prestigious 26.2-miler, which moved from its traditional spring date for the first time in its 125-year history because of the coronavirus outbreak.