18世纪20年代，军事飞行员驾驶着载满带电沙粒的飞机去袭击云层，尝试人工造雨并且清除雾层。

In the 1920s airplanes loaded with electrified sand were piloted by military aviators who "attacked" the clouds in futile attempts to both make rain and clear fog.

youdao

暴风云只降下10%水分成为雨或雪，而自1950年代起采用的“云种散播”，可催化降下更多水分。

Storm clouds drop as little as 10 percent of their water as rain or snow, but "cloud seeding" has been used since the 1950s to coax more from them.

youdao

虽然有清一代留下了大量的史料，如《晴雨录》、《雨雪分寸》、《粮价单》等，但是目前仍不能把这些因素结合起来。

Although the Qing Dynasty left a lot of historical data, such as "precipitation record", "snow measured", "single grain" and so on, but there is still not able to combine these factors.

youdao