We spend about one-third of our lives asleep. Sleep is important to us. A good sleep gives us energy and makes us feel happier. If you need some good sleep, you can try the new bus service in Hong Kong. Hong Kong has opened a "Sleeping Bus Tour". The five-hour ride is for people who can't sleep well at night. Passengers can get eye masks, ear plugs (耳塞) and so on for better sleep.
Why do buses make people sleepy? Buses are a perfect environment that produces white noise. Buses get crowded with people going to and from work every day. Carbon dioxide (二氧化碳) increases when there are lots of people in a small place. When you were a baby, you were rocked (摇晃) to sleep. Sitting on a bus gives people similar experiences. Their rocking movements make people want to close their eyes. You may find it easy to fall asleep during the long bus trip.