__________car traffic in city centers and make the air cleaner, some countries made rules that drivers should pay extra money if they drive in the city centers.

The man____of shooting 6 school children was caught by Beijing police,the Xinhua News Agency reported on Friday[ ]

All the countries agreed to ______ an organization to help those kids left homeless in the earthquake.

Without proper lessons, you could _____ a lot of bad habits when playing the piano.

Mr. Smith insisted that his book _______within three days.