Perchloroethane
六氯乙烷
🗣️ 情景例句
I consider him my best friend.
我将他视为我最好的朋友。
I know the boy whose father is a college president.
我知道那个男孩的父亲是大学校长。
it requires 97 per cent less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200 mile-journey from Earth's surface into orbit!
因此，从月球到地球的25万英里所消耗的能量要比从地球表面进入地球轨道的200英里所耗能量少97%。