Jenny is on holiday now. I wonder ________.

A．when she will come back

B．when she came back

C．when will she come back

D．when did she come back

下列对骨质疏松描述错误的是（）。

A.骨质疏松症可分为原发性、继发性两类

B.雌激素可抑制骨吸收，雌激素水平不足是病因之一

C.多数患者为原发性骨质疏松症

D.女性绝经期后发病率升高

E.骨折是本病最为严重的后果