—You should take exercise in your spare time.

—I want to, but the little time I have outside of school is     with part-time job.

A．taken away

B．taken in

C．taken out

D．taken up

生产、生活离不开各种化学物质，下列说法正确的是                                                       

A．纳米材料是指一种称为“纳米”的新物质制成的材料

B．光导纤维是由高纯度的硅制成的通信材料

C．王水是浓硝酸和浓盐酸的混合物

D．绿色食品是指不含任何化学物质的食品