Fleming discovered penicillin almost by______.
The engine of the car went out of order and the bad weather _____ the helpless of the driver.
With a large amount of work ______, the chief manager couldn’t spare time for a holiday.
How much more expensive do you think a flat in a downtown area is than ______ in a suburban area?
is widely acknowledged that there is life, there is hope.
"Those responsible for the accident be punished while those contributing to solving the problems be rewarded," promised the official then and there.