Some children want to be writers some day. They mean that they want to write stories or books for people to read. That's good! It's good to write something for people to read! But they should know that they need to be good readers first before they really are good writers. They should read a lot of books, and read for hours and hours every day instead (代替) of watching TV and spending a lot of time playing games when they are free.
If you are a good reader, it doesn't take you long to do the reading homework. Then you have time to read many other books for fun. Because you read so well, you have more fun in reading and you want to look for more books to read.
Before you decide to be a good writer, you'd better say to yourself, "I must read and read and read more and more!"
2NH3(g)在10L的密闭容器中进行，测得 2min内，N2的物质的量由20mol减小到8mol，则2min内N2的反应速率为 （ ）