4 Put the verbs in brackets into the Present Perfect or Present Perfect Continuous. Stonehenge (0) has been (be) the subject of archaeological debate for many years. No one ...... (yet/explain) satisfactorily why or how it was built, although teams of experts (2) (excavate) the site for years and a team of American scientists (3) .... .............. (recently/start) working in the area with sophisticated new equipment. Popular theories (4). .... (suggest) that Stonehenge was built as a temple, but no one (5)... (manage) to work out how the stones were transported here. A group of students from Bangor University (6) (discuss) the possibility of re-enacting the journey from Wales, where such stones are to be found, overland to Stonehenge and sponsors (7).... ........ (come) forward with offers of financial assistance. The British Museum (8) forthcoming exhibition of artefacts period which they (9)......... last five years from all over Northern Europe. ********** ******* ******* ******* .... (also/announce) a from the Stonehenge ...... (gather) over the 7​