According to story by Procopius, Byzantine emperor Justinian obtained the first silkworm eggs in 552 CE.
根据普罗科匹厄斯的故事，拜占庭皇帝查士丁尼在公元552年得到了首批蚕卵。
2
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。
3
The CC-CE combined amplifier has the nicer wide band magnifiable characteristic.