Задание №45340 ЕГЭ по Английскому языку

Before Stonehenge 

The                          (EARLY) structures known in the immediate area are four or five pits, three of which appear to have held large pine ‘totem-pole like’ posts erected in the Mesolithic period. It                          (NOT KNOW) how these posts relate to the monument of Stonehenge. At this time, when much of the rest of southern England was largely covered by woodland, the chalk downland in the area of Stonehenge may have been an unusually open landscape. It is possible that this is why it became the site of an early Neolithic monument complex                          (DATE) back to the period between 8500 and 7000 BC.