We can identify the age of a dinosaur by measuring the amount of its residual carbon.
The approximate age of plant and animal remains can be estimated by measuring the amount of its residual (radio)carbon.
The date at which plants and animals died can be estimated based on the half-life of carbon.
放射性炭素年代測定=Radiocarbon dating、carbon(-14) dating (method)
半減期＝half-life
カジュアルな会話の中でしたら、以下のように言うことができます。
We can identify the age of a dinosaur by measuring the amount of its residual carbon.
We can use carbon dating to identify the age of a dinosaur.
The approximate age of plant and animal remains can be estimated by measuring the amount of its residual (radio)carbon.（残存する（放射性）炭素の量を測定することによって、植物および動物の残存物のおよその年齢を推定することができる）
The date at which plants and animals died can be estimated based on the half-life of carbon.（植物や動物が死亡した日は、炭素の半減期に基づいて推定することができる）
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