More and more of the word’s population are living in towns or cities. The speed at which cities are growing in the less developed countries is＿＿（36）＿＿. Between 1920 and 1960 big cities in developed countries＿＿（37）＿＿two and a half times in size, but in other parts of the world the growth was eight times their size.
The＿＿（38）＿＿size of growth is bad enough, but there are now also very＿＿（39）＿＿signs of trouble in the＿＿（40）＿＿of percentages of people living in towns and percentages of people working in industry. During the nineteenth century cities grew as a result of the growth of industry. In Europe the＿＿（41）＿＿of people living in cities was always smaller than that of the＿＿ （42）＿＿working in factories. Now, however, the＿＿（43）＿＿is almost always true in the newly industrialized world:（44）.
Without a base of people working in industry, these cities cannot pay for their growth; ＿＿（45）＿＿. There has been little opportunity to build water supplies or other facilities. ＿＿（46）＿＿,a growth in the number of hopeless and despairing parents and starving children.
