From C5 to C14, slowly I became a good English speaker and a more confident teenager.

从C5到C14，我的英语能力逐渐提高，并且在与外教们的沟通中建立了更好的自信。

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Daqing diesel carbon Numbers distribution mainly concentrates in C14 ~ C18. the peak value basically is close, carbon Numbers distribution relative centralism.

大庆柴油的碳数分布主要集中在C14 ~ C18，峰值基本相近，碳数分布相对集中。

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Dr Morris added that artefacts from the site would need to be very carefully analysed, and pointed out that the C14 carbon dating process is not without its error margins.

BBC: Lost city 'could rewrite history'