Passage 1
Questions 1 to 5 are based on the following passage.
The debate about the origin of Stonehenge＇s（英格兰巨石阵）grandest lumps of rock had been raging for at least four centuries. Now, thanks to the recovery of a chunk of the monument that had been lost for decades, archaeologists have finally been able to reveal where they came from.
The research shows that the giant sarsen（砂岩）stones were gathered，some 4,500 years ago, from the West Woods, a site covering 
square miles on the edge of Marlborough Downs in Wiltshire. It is about 15 miles north of Stonehenge and it seems likely that its nearness made it attractive.
Susan Greaney , a historian for English Heritage, said :"We can now say that when
sourcing the sarsens, the dominant objective was size-they wanted the biggest, most substantial stones they could find and it made sense to get them from as nearby as possible. "
The breakthrough was made possible by the discovery of a metre - long core of rock that was drilled from a stone during a restoration in 1958. The project had involved three sarsens that had fallen more than 150 years earlier being dragged upright and made stable.
Robert Phillips worked for a company asked to drill through one of the stones so that it could be pinned into place with a metal bracket. He was allowed to take the core home. lt hung on his wall ,in a tube, for 60 years, accompanying him to Florida when he moved there. When Mr Phillips recently passed away his family offered to return the core. This gave researchers the chance to analyse material from the interior of a monument closely guarded as a World Heritage Site.
There are thought to have been about 80 sarsens at Stonehenge originally and 52remain. They include the 15 stones of Stonehenge's central horseshoe ,the uprights and beams of the outer circle, as well as outlying stones. While the smaller bluestones had been traced to specific locations in the Preseli Hills in Wales, the source of the larger sarsens had been impossible to accurately identify until now.
Ms Greaney said : "To be able to locate the area that Stonehenge's builders used to source their materials around 2,500 BC is a real excitement. Now we can start to understand the route they might have travelled. "
What can we learn from Susan Greaney ' s remarks in the last paragraph?
A、It is still unknown why Stonehenge was constructed.
B、Stonehenge's builders struggled to source the stones.
C、Fifteen sarsens of Stonehenge were found in Wales.
D、The route the stones travelled has yet to be known.
【正确答案】：D