periodo-carbon

例句：

1. 1. The discovery of carbon-14 has revolutionized the study of paleontology.
   碳-14的发现使古生物学研究发生了革命。
2. 2.The molecules of carbon dioxide are responsible for the greenhouse effect.
   二氧化碳分子负责温室效应。
3. 3. Carbon is a key element in the production of steel and other metals.
   碳是生产钢铁和其他金属的关键元素。