幼儿开始能以自身为中心辨别左右方位是在（ ）。
A、3岁
B、4岁
C、5岁
D、7岁

A．Profit on the sale of an office building
B．Revenue from sales inventory
C．Interest received from investments held by the business
D．Sale from provide service

A．牧养
B．圈养
C．单独养
D．群养