英文構造
⑩ History tells [ how people lived in the past]. The oldest written history (in the
S
V
o how SV 「どのように~するか」
world) goes back six or seven thousand years,/but/humans had been living on earth/
過去完了進行形 《継続〉「(ある時まで)ずっと〜していた」
「(過去に) さかのぼる」
for many thousands of years/before that time.
・・・・の間(期間)
=記録に残る歴史の時代
We do know that < in the days of the earliest human beings>,/most of the land