Additional epidemiological, environmental and food trace-back investigations are under way.
其它的流行病学、环境和食品反向追踪调查正在进行中。
2
Like a family tree that you might use to traceback through generations of ancestors, only it's showing a family of genetically related languages instead of people.
就像你可以追溯祖先的家谱一样，它只是在显示与遗传相关的语言，而不是人类。
3
Rather than merely a sign, it is the root from which we can traceback to our ancestor, the tie that helps bind us to other members of the same clan, the dignity most people hope to live for.