American International Group was the largest insurance company in the US_______it, suddenly closed down in September 2008.
Due to the widespread ________ of this medical technology,more diseases can be discovered and treated at an early stage.
The book was written ______ careful observations and detailed studies.
You had better ______some time every day for sports so that you can keep yourself energetic.
Don’t take it seriously, Alice. I wasn’t making ______ fun of you — it’s nothing but ______ joke.
My neighbor asked me to go for _____ walk, but I don’t think I’ve got ____ energy.