Read the passage and choose the correct answers.

In 2018, the United Nations announced that Singapore was completely (16) ______ as 100 per cent of its population is defined as urban. Urbanisation has brought both (17) ______ and disadvantages to the small city-state. On the one hand, Singapore has attracted a lot of skilled workers from many other countries to ensure the economy continues to grow. Migrants have also helped create a more culturally diverse society in Singapore. On the other hand, urbanisation has caused some serious problems such as deforestation, overpopulation, and waste management. Since it was first colonised by the British in 1819 and Singapore was formally founded, over 95 per cent of its vegetation has been (18) ______. In terms of (19) ______ density, in many parts of Singapore, there are over 20,000 people living per square kilometre. Waste treatment used to be another (20) ______ in Singapore. However, thanks to the development of technology, this problem has been solved. Singapore has even become a leader in urban waste management.