Read the following passage and choose the item (a, b, c, or d) that best answers each of the questions about it.
Japan’s cities also have a mix of traditional and modern characteristics. There are tall office and apartment buildings as well as traditional wooden houses. Many people prefer to live near the center of cities, but because houses there are expensive, they often commute from suburbs. Traffic, pollution, and crowds are problems.
However, there is little crime, and even very crowded cities have many parks and gardens.
characteristic (n): tính chất
commute (v): đi làm xa crime (n): tội ác
What does the word ‘they’ in line 4 refer to?
cities characteristics buildings people