The frescoes portrayed scenes of ancient human life. 这些壁画表现了古人类的生活场面。
But the tools of biotechnology have become so powerful that it's now possible to deduce ancient human history from a drop of blood or a few shed skin cells. 但是生物技术工具已变得如此强大，现在只要有一滴血或几片蜕皮细胞我们就能推断出古人类的历史。
