Tell me the meaning of the following sentences.

It's cold in winter, and the snow often doesn't melt easily. The snow covered on the soil is soft, which hides a lot of stagnant air and does not transfer heat. It's like covering a crop with a quilt. No matter how cold it is outside, the temperature below will not drop very low. When snow melts, water stays in the soil, which is very beneficial to spring ploughing and sowing and crop development. In addition, snow also contains a lot of nitrogen compounds, which are brought to the soil as the best fertilizer when the snow melts. Therefore, several heavy snows in winter are a sign of a bumper harvest in the coming year.

2. Ning's reliability, no confidence.

I would rather trust the scale of a ruler than my own feet.

It's the story of Zheng people buying shoes.

Zheng has a man who wants to buy a pair of shoes. He measured his feet first, and then put the measured size on the seat. He hurried to the market and forgot to bring that size. He got the shoes, but said, "I forgot my size." "Go home and get it. By the time he came back, the market had already dispersed, and he finally didn't buy shoes. Someone asked him, "Why don't you try on the size of your shoes with your own feet?" He replied, "I would rather believe in size than my own feet!" 」

Keep it and don't lose it.

"Keep" literally means to hold or guard; "lost", lost.

Get it, have it, keep it, and never lose it again.

4. Spring blossoms and everything is brilliant.

This is a line in Yuefu poem "Long Songs", which means that the sunshine in spring is spreading his favor, and all the creatures on the earth are shining.