Some children want to challenge themselves by learning a language different from ______ their parents speak at home.
With the price of ______ petrol rising, the bicycle may become ______ popular means of transportation again.
________all kinds of difficulties,the workers have made rapid progress in the construction of the World Expo 2010 Shanghai.
_______of the household rubbish________recycled or reused since the new technology was applied.
Health problems are closely connected with bad eating habits and a________of exercise.
---Could I borrow your car for a while?--- _________. I won’t use it today.