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。
2
The CC-CE combined amplifier has the nicer wide band magnifiable characteristic.
共集-共基组合放大电路具有更好的宽带放大特性。
3
According to story by Procopius, Byzantine emperor Justinian obtained the first silkworm eggs in 552 CE.