All of the flowers now raised here have developed from those _____ in the forest. [ ]

A. once they grew

B. they grew once

C. they once grew

D. once grew

“小油脂，大道理”。少女体内脂肪含量正常，才能正常产生性激素，促进少女的女性第二性征的发育，形成特有的女性美。因害怕发胖而拒食含脂肪食物的做法是不足取的。下列物质属于油脂的是 [ ]

①②③④润滑油⑤花生油⑥石蜡

A．①②

B．④⑤

C．①⑤

D．①③