serious
The concentration of carbon dioxide in the Woods is too high in the morning, and the air is not fresh.
Just because people live in cities and are used to being polluted, they think it's good to be in the Woods in the morning.
In fact, it is best when the sun shines into the Woods after ten o'clock.
Because at this time, the photosynthesis of trees can reach its peak, absorbing a lot of carbon dioxide and releasing oxygen.
Be beneficial to people's health.