Exercise 6. Fill in the blanks with the correct prepositions. It is now almost certain that global warming has been directly caused (1) fossil fuels. This has led (2) man's use of an international debate about what we should do to reduce the negative effects (3) our actions and how we can make the planet safe for our children's children to live in. One consequence (4) this debate has been to improve the level of greater awareness of this difficult "green" education in schools and this should result (5) issue in the long term. However, in the short term there still remains much to be done. The reason (6) this is that we need to address causes (7) the immediate problem. the hor