A) on occasion E) proceed I) insert M) in terms ofB) critical F) make up for J) reliance N) relevantC) frown G) investigate K) exaggerate O) phenomenaD) mattered H) acquire L) promote11. To buy a drink from the machine, first ______ the correct coins, then select the drink you want and press the button.12. The economy is just one of the several ______ problems the country is faced with.13. A basic understanding of mathematics is needed to explain a wide variety of natural ______.14. They are doing a research project to ______ the harmful effects of air pollution in the city.15. As for Laura and me, the colour of our skin has never ______, either in the workplace or on social occasions.16. She is not considered an outstanding student. But ______ she has surprised her parents with her excellent performance.17. The World Trade Organization was established to ______ trade among its member states.18. We are here to discuss how to proceed with our investigation. What you are saying is not ______.19. Hard work can often ______ a lack of intelligence.20. To reduce our ______ on foreign technology, we must invest more in research and development.

A) on occasion E) proceed I) insert M) in terms of B) critical F) make up for J) reliance N) relevant C) frown G) investigate K) exaggerate O) phenomena D) mattered H) acquire L) promote 11. To buy a drink from the machine, first ______ the correct coins, then select the drink you want and press the button. 12. The economy is just one of the several ______ problems the country is faced with. 13. A basic understanding of mathematics is needed to explain a wide variety of natural ______. 14. They are doing a research project to ______ the harmful effects of air pollution in the city. 15. As for Laura and me, the colour of our skin has never ______, either in the workplace or on social occasions. 16. She is not considered an outstanding student. But ______ she has surprised her parents with her excellent performance. 17. The World Trade Organization was established to ______ trade among its member states. 18. We are here to discuss how to proceed with our investigation. What you are saying is not ______. 19. Hard work can often ______ a lack of intelligence. 20. To reduce our ______ on foreign technology, we must invest more in research and development.