正在看Caring for your baby and young child一书中关于４－７个月时宝宝成长的描写。很有意思，节录一段：
"Another major discovery that your baby will make during this period is that objects continue to exist when they're out of her sight-a principle called object permanence. During her first few months, she assumed that the world consisted only of things that she could see. When you left her room, she assumed your vanished; when you returned, you were a whole new person to her. In much the same way, when you hid a toy under a cloth or a box, she thought it was gone for good and wouldn't bother looking for it. But sometime after four months, she's begin to realize that the world is more permanent than she thought. You're the same person who greets her every morning. Her teddy bear on the floor is the same one that was in bed with her the night befor. The block that you hid under the can did not actually vanish after all. By playing hiding games and observing the comings and goings of people and things around her, your baby will continue to learn about object permanence for many months to come.
Isn't it interesting to learn these stuff?
