William has cut his smoking_____to five cigarettes a day.
A
cutdown“削减，减少”;cutsth.downto“把⋯⋯减到(什么程度)”，是固定搭配，而且符合题意。
He‘sworkinghard_____.
It was not until she had finished all her work_____.
Children who are over-protected by their parents may become_____.