17 Read and complete in your notebook. Use: oldest, cleanest, busiest. London in the UK is one of the D - cities in the world Thousands of people visit this cx city every year. It is THE capital to visit If you want some fun! Varanasi, on the banks of the river Ganges in India, is one of the 2) - cities in the world. It is thousands of years old and is home to poets, writers and musicians. It is called the cultural capital of India Singapore, in south-east Asia, is a large modern city. It is one of the 3) ... cities in the world - you can't drop litter or chew gum in this city!