I’ m sorry, I mistook you ___ your sister ___ mistake.
I have never dreamed of _______ for me to win the first prize in the 1000-meter race.
— Why does the river smell terrible? — Because large quantities of polluted water _______ into it.
Xi’an was the last city ______ he visited when he came to China.
The music ______ she is dancing sounds beautiful.
______ time ______, what the scientist said finally proved to be true.