已知有一个字典对象a，创建一全它的拷贝b的正确的语句是：（ ）
A、b = a
B、b = a.copy()
C、b = copy(a)

单项选择题电影院座位对位排列，其视线升高值为（）mm。

单项选择题In which life stage do we explore personal relationships and later focus on our career and family? A、Infancy. B、Old age. C、Adulthood. D、Adolescence.