将带芽的马铃薯块茎埋入土壤中进行繁殖的方法是（　　）

A．种子繁殖

B．孢子生殖

C．出芽生殖

D．营养生殖

_____ quite recently, most mothers in Britain did not take paid work outside the home.

A．Before

B．Until

C．From

D．Since