Which of the following would be best to help prepare a preschool-aged child for an injection

A. Having an older child explain that shots do not hurt.
B. Helping the child to imagine she is in a different place.
C. Giving the child a play syringe and a bandage to give a doll injections.
D. Giving the child a pounding board to encourage expressions of anger.

720900=（    ）万                   9004700000=（    ）亿  

650700000=（    ）万              40300000=（    ）亿