The differences are what interest me, because the one on the left was made to a pretty unvarying design for about a million years -- from one-and-a-half million years ago to half a million years ago.
二つの間の相違が興味深いのです 左の石斧の形は 100万年ほどの間 つまり 150万年前から50万年前まで 変化しませんでした