We must work hard to _____ a good knowledge of English.
Washing machines made by China have won worldwide attention and Haier has become _____ popular name.
If you buy more than ten, they knock 20 pence off ______.
In order to find _______ better job, he decided to study _________ second foreign language.
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.