He's unlucky , and he's always suffering _____ luck one after another .
—How about __________ Christmas evening party?—I should say it was __________ success.
I looked under __________ bed and found __________ book I lost last week.
Students should be encouraged to use _____ Internet as _________ resource.
The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ____ 9-story building.
We can never expect bluer sky unless we create less polluted world.