Sure, let's fill in the blanks with the most appropriate words:

23. **C. changing**
"Nowadays, education is changing a lot with the help of technology and AI."

24. **A. electronic**
"Through their computers and other electronic devices, they can participate in lifelike simulated lessons anywhere."

25. **B. tests**
"Students can even do all the tests online and get the results right away."

26. **D. future**
"In the future, online learning will become an effective way for children as well."

27. **C. because**
"This kind of education is time-saving and cost-saving because they don't have to use any vehicles to travel a long way to go to school."

28. **D. disappointed**
"However, some students are disappointed about virtual learning because they like to communicate with others in real life."

So, the completed passage reads:

"Nowadays, education is changing a lot with the help of technology and AI. Going to university or the library is not the only way for students to gain knowledge today. Through their computers and other electronic devices, they can participate in lifelike simulated lessons anywhere. Students can even do all the tests online and get the results right away. In the future, online learning will become an effective way for children as well. They can stay at home and have access to various classes through their computers. This kind of education is time-saving and cost-saving because they don't have to use any vehicles to travel a long way to go to school. After the COVID-19 pandemic, online education has been the main option for many schools all over the world. However, some students are disappointed about virtual learning because they like to communicate with others in real life."