第四句：
中国的春节、中秋节等传统节日的日期都基于农历。
译文一
Traditional Chinese festivals such as the Spring Festival and Mid-Autumn Festival all derive their dates from the lunar calendar.
思路：客观事实，用一般现在时。
译文二
The dates of traditional Chinese festivals such as the Spring Festival and the Mid-Autumn Festival are all based on the lunar calendar.
译文三
The dates of traditional Chinese holidays, including the Spring Festival and the Mid-Autumn Festival, fall on days determined by the lunar calendar.
思路：including 替代 such as，也是常见的举例表达。
注：
1、这句话的核心是“日期基于农历”，但主语可以是“节日”也可以是“日期”。
如果以“节日”为主语，就说 festivals are based on the lunar calendar，意思是“节日（的确定）基于农历”。这是一种省略的说法，但完全可以接受。
如果以“日期”为主语，就说 the dates fall on days determined by the lunar calendar 或 the dates are set according to the lunar calendar。这种表达更精确，明确指出是“日期”基于农历，而不是节日本身。
2、词汇选择：
基于：be based on… /be determined by… /follow…
春节：the Spring Festival / Chinese New Year
