Trees can stop the sand _____ towards the rich farmland in the south.
—Have you finished your homework? —Not _____. There are still some exercises to be done.
—What did our geography teacher say? —She told us that the earth _____ around the sun.
Has your sister succeeded_____ the first place at the university this term?
The cleaners must prevent the street _____.
---Jim, you speak so fast, I can’t_____you.. ----Oh,sorry, I will say it again slowly.