Raising pets is a popular online game among teenagers. "More than 20 of my classmates have adopted  pets online." Said Wang Hui from Beijing. If you go to some websites, you can adopt virtual  pets like penguins , chickens, dogs and elephants. You can feed, wash, talk to and play with your pet. Dai Yingshuang of Shanghai said, "It's great fun and I have also learned how to take care of others." She usually asks her uncle to take care of her pet while she is at school. If you don't feed and care for the pet, it will become unhappy and unhealthy. So raising an online pet means spending a lot of time online. This makes many parents worried. They fear it will have a bad influence on the children's studies. Wang Zhaotong from Anhui has raised a penguin since last year. She said, "My parents know about the penguin and think it's okay." If the students can keep the _ between studying and playing, it's not bad for them to "raise" pets online. Over   _   students in Wang Hui's class have adopted pets online.
10 20 half 21