--- Can I see the headmaster at the moment, please?

--- I'm afraid not. He _______out. He _______ in 10 minutes.

A．goes; comes

B．has gone; came

C．went; will come

D．has gone; will come back

母孕年龄越大，期所生子女患病的可能性越大的疾病是（）

A.脆性X综合症

B.Down综合征

C.Klinefelter综合征

D.Turner综合征

E.以上都不是