You picked up your daughter, who is 9 years old, from soccer practice after a difficult day at work. she asks you if you are ok and says that you seem to be unhappy with something. is this perceptiveness in a child her age unusual?

This is not unusual because at 9 she's already either in 3rd or 4th grade, has fairly extensive knowledge, and is no longer in a selfish phase of mental development. At age 9 you can perceive emotions from other people especially ones you are close to. How the other person shows that emotion determines how perceptive the child will be, but it doesn't have to be blatant for her to understand how you feel.

It allowed for things to be produced much more quickly and efficiently