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src/why-exercise.md

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+# Rust By Practice
+
+Practice Rust with easy to hard examples, exercises and small projects.
+
+## Read it online
+
+- [English](https://practice.rs)
+- [Chinsese](https://zh.practice.rs)
+  
+## Why another?
+
+[Rustlings](https://github.com/rust-lang/rustlings) and [Rust By Example](https://github.com/rust-lang/rust-by-example) are absolutely very nice, but we provides a little more:  
+
+1. We have more exercises of which the difficulty is from easy to hard
+
+2. Covers more topics in Rust, such as **async/await, threads, sync primitives, optimizing and stand libraries** etc
+   
+3. Learning from small projects, for pratice
+   
+4. Both English and Chinese are supported
+
+## How to use
+
+- You can edit and run the exercises online
+  
+- **The goal is to make each exercise comipile with NO ERRORS and Panics !**
+  
+- Difficulty level: easy: 🌟  medium: 🌟🌟 hard: 🌟🌟🌟  hell: 🌟🌟🌟🌟
+
+
+## Contributing
+
+All kinds of contributions are welcomed, such as exercise proposing, typo and bug fixing.
+
+
+## Buy me a ... 🌟?
+
+Fo us, a github star will be better than a cup coffee, and it only costs you 0 cents :)