3. Among the following solar terms, the day in Beijing is the longest and the closest.

Solar terms with the same distance from summer to day or the same distance from winter to day have the same latitude of direct sunlight, the longest day or the closest night.

Qingming is the first five squares of summer solstice, and rain is the first eight squares of summer solstice. A is wrong.

Beginning of winter is three squares before the winter solstice, and beginning of autumn is nine squares before the winter solstice. B is wrong.

Light snow is the two squares before the winter solstice, and cold is the two squares after the winter solstice.

Before the summer solstice, the rain is eight squares, and after the summer solstice, the summer heat is four squares. D is wrong

Answer: c, light snow, great cold