Precontamination
初期污染
🗣️ 情景例句
It's almost ten o'clock.
差不多十点了。
Knowledge will not be aquired without pain and application.
不花力气，不下功夫是得不到知识的。
Look at those black clouds. It's going to rain.
看那成堆的乌云，要下雨啦！