When appropriate and desirable behaviors earn points or tokens that can later be exchanged for rewards, which of the following techniques is being used?

According to Piaget, children ages 2 to 6 are most notable cognitively for what they are unable to do, such as ____

perform mental operations coordinate senses with motor activities use language to assist with thoughts use images to create mental representations

First-born children tend to adopt a(n) ____ style in their productive/expressive language usage

a. sensitive-period b. expressive c. vocable d. referential