— Were you busy last weekend?

— Very. Rather than ____ time playing cards as usual, I devoted every myself to ____ an advertisement. [ ]

A. wasting; making

B. waste; make

C. to waste; make

D. a waste of; making

退火是将钢加热到一定温度（）冷却的热处理工艺。

A、随炉缓慢

B、在空气中

C、在水中

D、在油中