He reminded his daughter that only after _______a secretary and other staff_______able to concentrate on marketing.

A．she could afford;would she be

B．she could afford;she would be

C．could she afford;would she be

D．could she afford;would she be

有些基因在一个生物个体的几乎所有细胞中持续表达，这类基因称为

A．可诱导基因

B．可阻遏基因

C．管家基因

D．启动基因

E．操纵基因