When I work out at the gym, I always work ______ a sweat. 

I need to buy a new pair of shoes. The one's I have are completely worn _______ .

I studied English  2 years ago, but I need to brush ______ ______ my grammar.

After a 2 year break, the pop singer is once again popular and definitely _______ _______ track. 

They should have arrived an hour ago. I wonder what's holding them ______.

I really don't like polluting the air, but a car is something I can't do _____________ .

 I missed meetings while I was out of the office. Can you please bring me ____  _____ speed. 

We keep on making the same mistakes. We seem to be running _________ in circles. 

We nearly made it home, but our car ran ____  ____ gas. 

Since he was the black sheep of the family, his brothers looked ________ ________ him.