The longest day in Harbin, Heilongjiang is () A. Equinox B. Summer solstice C. Equinox D. Winter solstice.

The summer solstice is the tenth of the twenty-four solar terms. "The spring rain shakes the spring and the valley days, the mountains and rivers in summer are hot in summer, the autumn dew is frosty, and there is snow and ice in winter."

From this song "Twenty-four solar term song", we can know that the two solar terms from summer to around are Miscanthus and Little Summer. On the day of the summer solstice, the sun moves to 90 degrees of the yellow meridian (summer solstice), and the position where the sun shines directly on the ground reaches the northernmost point of the year, almost directly on the tropic of cancer.

At this time, the sunshine time in all parts of the northern hemisphere reached the longest in the whole year. For the Tropic of Cancer and its northern area, the summer solstice is also the highest day of the year at noon.

Zhou Zundao, a poet in the Song Dynasty, wrote a poem "Summer of Solstice":

1929, the fan never left his hand;

3927, eat tea like honey juice;

4936, strive to stay in the street;

In 5945, autumn leaves danced on the trees;

6954, enjoy the cool and not enter the temple;

7963, sleeping to find sheets;

In 8972, sheets and quilts were added;

In 998 1 year, every family played with charcoal.