/kloc-what kind of knowledge was involved in walking on the ice in 0/929 and 3949?

1929 Don't do this: 1929 It's already very cold after the solstice in winter, so when you feel cold outside, you can't help putting your hands in your pockets.

Walking on the ice in 3949: In 3949, it was the coldest season of the year, and the river was frozen so thick that adults and children could walk on it.

In addition, due to the great difference in climate in China, the opinions in 3949 were slightly different. For example, in 3949, dogs were frozen in Jilin, and in 3949, Jiangsu patrolled the streets for the elderly who picked up feces.

Looking at the willows by the river in May, 1969: The coldest time in May, 1969 passed, the weather began to get warmer, and the branches of willows began to sprout green buds, which seemed to be green from a distance. In terms of time, the last day of May 9th is the "beginning of spring" in the 24 solar terms, which means that winter is over and spring is coming.

The river opens in July and September, and swallows come in August and September: In July and September, the ice and snow begin to melt, the frozen river surface will slowly thaw, and the gurgling sound will be heard. In August and September, swallows will fly back from the south to nest. In addition, some people say that geese fly to the north in August and September, but there is not much difference between "geese come" and "geese come".

1999, cattle were plowed everywhere: by 1999, the weather was warmer than before, and the second day of 1999 was a thorn in the 24 solar terms. When I woke up, the weather turned warmer, and spring thunder gradually appeared, most areas of China entered the spring ploughing season.