Why are people sub-healthy? Answer in English? Thank you. The exam is urgent.

First of all, people are in a sub-health state because of their living environment. Some of them work in very unhealthy conditions, such as miners, traffic policemen and workers in the textile industry.

Secondly, social pressure leads to people's sub-health. These people mainly work in air-conditioned offices, and they have to sit in front of computers all day. Due to lack of exercise and work pressure, they are often in a sub-health state.

Thirdly, students with heavy learning burden have little leisure time, and their lives are all about learning.