You’d better carry a(n) tyre in the back of your car in case it breaks down on the way.
The company had about 20 notebook computers but only one-third _______ used regularly. Now we have 60 working all day long.(2006浙江)
The country life he was used to ______ greatly since 1992.
The number of people invited ______ fifty, but a number of them _____ absent for different reasons.
When and where to go for the on-salary holiday ______ yet.
Every possible means ______ to prevent the air pollution, but the sky is still not clear.