Mr. Smith has two sons, one of____working as a bus driver.
All possible means _______. However, nothing can _______ him dying of lung cancer.
Do you think ________ life on Mars?
At the ________ news, there was a ________ expression on his face.
We were scared to death when the fire ________. Fortunately, it was put out before it caused much damage.
He has ________ letters to answer and has to work from morning to night.