Fill in the words and translate the sentences. a) environment d) nature g) lessen b) century e) during h) science c) save f) protection i) pollution 1) people all over the world are worried about the of 2) the branch of which deals with the relation of living things to their is called ecology. 3) the environmental is one of the most important problems of mankind. 4) considerable progress was made the second half of the 20th . 5) the mankind should first of all pollution. 6) we must do everything possible to the nature.