Regular reviewing is __good habit. If you stick to it, you will make great progress in your study.
You can’t imagine what great trouble they have _____ the problem _____.
. It was getting dark; I found a car _____ in a pool by the side of the road.
In January , 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
The old farmer, _____ the badly injured and burnt soldier, came out of the burning farmhouse, calling continuously for help.
To answer correctly is more important than _____.