Optimum structure
[化] 最佳结构
🧩 词语组成解析
🗣️ 情景例句
He lost his money due to his own carelessness.
由于大意，他丢了钱。
He has lived here for a year.
他在这儿住了一年。[持续到现在的行为]
While the men had been working inside the ship, the air-line had been giving off oxygen.
当工人们的在船舱里干活时，供气管一直在排放氧气。