Fill in the gaps with suitable prepositions or adverbs where necessary: 1. The plant’s operators decided to shut ___ the reactor. 2. Differences ___ people’s earnings depend ___ a wide variety ___ factors. 3. This trend will raise a number ___ issues relating __ the economic concerns ___ the country. 4. Huge advances ___ the development ___ technologies have substantially facilitated the production process. 5. The invention ___ printing ___ the 15th century completely changed the world. 6.The deal involved the supply ___ forty new aircrafts ___ the airlines. 7. The town was turned ___ a flourishing seaside destination.