A client with type 1 diabetes mellitus is pregnant for the second time. Her previous pregnancy ended in spontaneous abortion at 18 weeks’ gestation. She’s now at 22 weeks’ gestation. The nurse is responsible for teaching the client about exercise during her pregnancy. Which of the following statements indicates that the client has an appropriate understanding of her exercise needs ？（）

A．"I know I need to walk with a friend or family member. "

B．"I know I need to vary the times of day when I exercise. "

C．"I know I need to exercise before meals. "

D．"I know I need to drink fluids while I walk. "

根据BrodieX线头片观测显示，下述哪颗牙齿的位置最稳定（）.

A.上颌第一恒磨牙

B.下颌第一恒磨牙

C.上颌第二前磨牙

D.下颌第二恒磨牙

E.上颌第二恒磨牙