单数和双数的规律是什么

简介：Of the nine gates in the capital, six were closed today, leaving only three gates in the southern city for people to enter. The fleeing crowds were carrying young and old, in ragged clothes, with frightened expressions, as if the captives were behind them, and some people were walking. They fell dead on the roadside. Some lost their children, and some lost their parents. They threw themselves in front of the city gate and cried loudly.