学术界对这件青铜鼎是“司”是“后”的争议持续多年，2011年3月，中国国家博物馆负责人表示，它将正式更名为“后母戊鼎”，展品的标牌和解说词都将改为“后母戊鼎”。下列相关叙述准确的是（   ）
①体现了中国学者科学求实的精神 ②“后母”在这里表示墓主人的身份③此鼎更名并无重大意义  ④此鼎铸于春秋时期

对于有理数a，b，定义min 的含义为：当a≥b时，min ＝b；当a＜b时，min ＝a.

例如：min ＝－2，min $\left\{-3，-3\right\}$ ＝-3.

   The Blacks are English . Now they are in Beijing . This is their first visit to China.
   They are going to stay in China for three weeks . They want to learn some Chinese ,too.
   He likes driving in Beijing very much .Mrs Blacks is a teacher .She often visits a middle school in Beijing ,and she likes to speak with students.
They take a lot of photos in China .When they are back to English ,They’re going to show the photos to their friends. They want the English People to know more about China.