[译] 天气已经好转。
[误] There has been an improvement on the weather.

[正] There has been an improvement in the weather.
[注] improvement in 指"在……方面有所改善"，又如：There is need for improvement in your method of study. 你的研究方法需要改进。improvement on（upon 或 over）指"与……对比的改善"，如：This is an improvement upon your first attempt. 与第一次相比，这次你的尝试有所改善。/That is a great improvement over your last work. 与你上次工作相比，那是一个巨大的进步。