The idea is that around the year 1800 CE the human population became large enough, around a billion people, that its activities started altering the environment.
这种想法出现于公元1800年左右，当时人口变得足够多，大约有10亿人，人类的活动开始能够改变环境。
The CE mark indicates conformity.
CE标志表明符合标准。
The CE mark is mandatory for many products in Europe.
