Can I go back to Hong Kong and Guangzhou in one day?

It's ok to come back to Hong Kong and Guangzhou in one day, but the methods upstairs are not ideal. It takes time to queue up. The best way is to go: to guangzhou east railway station, take the through train to Hung Hom Station in Kowloon, Hong Kong at 8: 00 a.m., arrive at Hung Hom Station in Kowloon, Hong Kong at 10 a.m., return to Hung Hom Station in Kowloon, Hong Kong at 7: 00 p.m., and arrive at 9: 00 p.m.19 p.m., take this through train and stay in guangzhou east railway station and Hung Hom in Kowloon, Hong Kong. There are few people, so it saves time. If you take the bus or Guangzhou-Shenzhen train, you need to queue up to go to Shenzhen for entry and exit procedures. If it's too wasteful, you don't have enough time to visit Mong Kok.