We should spend ______ money solving ______ problems.
I can’t hear you _____, would you please speak it more slowly?
Yesterday my parents and I went to Tianyi Square, and we enjoyed _____ around there.
----- Your English is very good, who taught you?----- Nobody. I taught _____.
_____ he is ill, _____ he still goes to work.
-----_____ do you exercise?-----Once a week.