The spider hid under the eaves and slept, and there was always a spider on its foot that connected to the web of the corner of the house. If a flying bug hits the web, the spider moves and the spider soon gets the message and comes over to eat the snack.
4. Characteristics of passenger flow: the service population is about 200,000 people.
The city is the main component of human civilization, and the city is also the development of human civilization and progress. In the agrarian age, man began to settle; With the development of industry and commerce, urban rise and urban civilization began to spread. In fact, in the agrarian age, the city appeared, but the role was military defense and sacrificial ceremony, not have the production function, just a consumption center. At that time the city was small, because the surrounding countryside provided little food. Each city and its controlled countryside constitute a small unit, relatively closed and self-sufficient.