33. To improve your reading ability, you should ____ half an hour every day for learning new vocabulary.
The reason for his success is ______ he has worked very hard.
—Where is Bob? I cannot find him anywhere. —He have been off long. I heard him make a call just now.
_______ is known to us all is that Madame Curie, _______ life was devoted to science, won the Nobel Prize twice.
---Do you have anything in mind _______ you’d like for supper? ---Well, _______ is OK with me.
The price of vegetables _______ sharply since last month.