When a tree first starts growing in a certain area, it's likely that the 27 climatic envelope—the temperature, humidity, rainfall patterns and so on—suits it.
2016年12月六級真題（第一套）閱讀 Section A
A woman excused the interruption and handed me an envelope.
2017年高考英語全國卷2 完形填空 原文
Further up, the weather changes— low clouds envelope the mountainsides, which are covered with thick grass.
2019年高考英語全國卷I 完形填空 原文
Now think of your laptop, thinner than a brown-paper envelope, or your cellphone in the palm of your hand.