These minerals can be dated by radioactive decay techniques because of the very small quantities of radioactive trace elements they, in turn, contain.
这些矿物可以用放射性衰变技术测定年代，因为它们所含的放射性微量元素非常少。
Stone does decay, and sotools of long ago have remained when even the bones of the man who madethem have disappeared without trace.
石头不会腐烂，所以以前的(石器)工具能保存下来，虽然它们的制造者已经消失的无影无踪。
Stone does not decay, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.
石头是不会腐烂的。因此，尽管制造这些工具的人的骨头早已荡然无存，但远古时代的石头工具却保存了下来。
Stone does not decay, and so the tools oflong ago have remained when even the bones of the men who made them havedisappeared without trace.
石头是不会腐烂的。因此，尽管制造这些工具的人的骨头早已荡然无存，但远古时代的石头工具却保存了下来。
Stone dows not decay, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.
石头不会腐烂，所以这些很久前的工具已经存在了相当长的时间，甚至制造这些工具的人尸骨都已经消失的毫无痕迹。
Stone does not decay, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.
石头是不会腐烂的。因此，尽管制造这些工具的人的骨头早已荡然无存；但远古时代的石头工具却保存了下来。
Stone does not decay, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.
石头不会腐烂。因此，虽然制造这些工具的人的骨头早已荡然无存，但远古时代的石器却保存至今。
Stone does not decay, and so tools of long ago have remained when even the bones of the man who made them have disappeared without trace.
石头不会腐烂，所以很久以前的由石头制成的工具依然存在，即使制造它们的人的骨头已经消失的无影无踪。
Stone does not decay, and so tools of long ago have remained when even the bones of the man who made them have disappeared without trace.
石头不会腐烂，所以很久以前的由石头制成的工具依然存在，即使制造它们的人的骨头已经消失的无影无踪。
应用推荐