The nurse instructs the female client concerning hormone replacement therapy for menopausal symptoms. Which of the following points should the nurse include in the client’s teaching plan

A. Estrogen therapy eliminates the need for supplemental calcium intake.
B. Estrogen therapy can reduce the risk of menopausal bone loss.
C. The risk of uterine cancer is decreased after menopause.
D. Smoking is associated with a later onset of menopaus

如图所示，把一个光滑圆球放在两块挡板AC和AB之间，AC与AB之间夹角为30°，现将AC板固定而使AB板顺时针缓慢转动90°，则（）

A.球对AB板的压力先减小后增大

B.球对AB板的压力逐渐减小

C.球对AC板的压力逐渐增大

D.球对AC板的压力先减小后增大