But each one of these is a different age, and if we can find out how old they are and then we can measure those chemical signals, this helps us to find out what's been going on in the ocean in the past.
但是每一个样本都来自不同的时代， 如果我们可以知道它们有多古老， 然后我们去测定 其中的化学信号， 这就可以帮助我们 研究出古代海洋中 发生了怎样的事。