The tree must ________ three times a week.
The trouble with such resources as coal, oil and gas ______ that they are not renewable.
Besides being able to walk on for three days without drinking, camels can also live for a long time ______ small quantities of food.
On the double 11th day, my uncle’s online store has successfully sold _____ shoes as last year, that is, it can hardly make ______ progress.
All the students don’t want ________ any misunderstanding among them.
---- Have you bought the newly-produced equipment on display? ----- Not yet, for I still prefer ______ at my home.