During the interim period, air quality has deteriorated.

【interim】在过渡期间，空气质量下降了。

By the first day of September, I will have my possession — 250,000 dollars which will come to me in various amounts during the interim.

到 9 月 1 日，我将拥有 25 万美元，在此期间，我将以不同的数额逐步获得这些钱。

By the first day of September, I will have in my possession two hundred and fifty thousand dollars which will come to me in various amounts during the interim.

到 9 月 1 日为止，我将拥有 25 万美元，在此期间，我将通过不同的数额逐步获得这笔钱。