①“中秋节”英语到底几种说法？

Mid-Autumn Festival

The Moon Festival

②The date varies! —日期每年都在变
It is not August 15th.它不是在8月15号（这里用August指的是阳历）

It is on the 15th of the 8th lunar month.而是在农历第8个月的第15天

③why it is called the moon festival?—为何也被叫做月亮节？

It is a "full moon day". It is generally believed that the moon is the brightest at that day.

因为这一天是月全的一天，也是被认为是月亮最亮的一天

⑤An Important Day for Family Reunions

—家人团聚的一天
when the festival comes, people always try their best to go back home from every corner of the world to celebrate the festival with their families.

当这一天到来时，人们从四面八方赶回家里，和家人一起庆祝。

⑥Eating mooncakes is highly symbolic! —吃月饼是最有象征意义的。

In Chinese culture, roundness symbolizes completeness and togetherness.

在中国文化中，原代表团团圆圆。

⑦It Is Also Celebrated in Other Asian Countries
Vietnam, South Korea, Singapore, Japan, the Philippines [ˌfɪlə'pi:nz], and Malaysia