–What about going to the movie tonight, Alan?--Sorry, I am busy ____ a report. ______, it is raining cats and dogs.
Beijing is one of the ______ in the world today.
Eating some vegetables is good ______ your health.
Jim’s parents enjoy _____ in the countryside.
My shoes are cheaper than _____.
_____ he was tired, _____ he didn’t stop to have a rest.