🧩 词语组成解析
[植]蓼属
🗣️ 情景例句
How long?
多久？
How long have you had this pain?
疼痛多久了？
This would solve the problem of ventilation, for if a train entered this tunnel, it would draw in fresh air behind it.
因为如果有列火车开进隧道，它就把新鲜空气随之抽进了隧道。