Heidi is shown 16 flowers, 4 of which are blue and 12 of which are red. Asked, "Are there more red flowers or flowers?" Heidi, a preoperational child, responds, "More red flowers." This problem demonstrates Heidi's difficulty with

Hector is conducting a job analysis, during which he observes that several elements are involved when a waiter takes a customer's order. These include asking for the order, writing down the order, and retrieving the customer's menu. Collectively, these elements constitute a:

A) position. B) job. C) task. D) domain.

Melody is eight weeks pregnant and wants to find out as soon as possible whether her unborn baby has any genetic disorders. Which prenatal diagnostic technique would be most appropriate to use?

a. amniocentesis c. fetal surgery b. ultrasound d. chorionic villus sampling