PREPOSITIONS. (giới từ) 1)People are destroying the air by adding pollutants _____ it. 2)Tropical forests have supplied us _____ many sorts of plants for food, medicine, and industry. 3)We all regard pollution _____ a serious matter to human beings. 4. Our major sources of energy are now running ______. 5. It is automobiles that provide millions of people ______ transportation.

1)People are destroying the air by adding pollutants __to___ it.                                                                  2)Tropical forests have supplied us _with____ many sorts of plants for food, medicine, and industry.                                                                                                                                                                                3)We all regard pollution _as____ a serious matter to human beings.                                                        4. Our major sources of energy are now running _out _____.                                                                 5. It is automobiles that provide millions of people __with____ transportation.