My friend John has got a restaurant in a big city. It is near a supermarket. He gets ten robots for the restaurant. Each robot costs   20,000 yuan. The restaurant is not big, but very popular. Now more and more people come here for dinner. The robots have different jobs in the restaurant. Two robots cook different kinds of food; one washes the dishes; one cleans the floor and the others give food to the guests  . Although robots do most of the jobs in the restaurant, John is still very busy. He must do many things to keep the robots working well. Luckily, John is good at studying robots and he knows robots very well. I think in the future, there will be a lot of robot themed restaurants   around the world. From the passage we can learn   _  .
John's restaurant is in a small city John is always free because of the robots the robots cost John 200,000 yuan there are two robots sweeping the floor in the restaurant