1）The villagers didn't realize how serious the pollution was until the fish in the river were all dead.
2) The study method introduced by the class monitor was proved to be very effective.
3) The banlanced diet could make people keep fit.
4) The subway is of great benefit to the resident around the area.
5) In some aspects, the city life can't compare with the life in the country.
6) With the development of science technology, agriculture becomes more and more colorful.
保证全对!