update chinese faq translation。

意译非直译

Author: gerryxiao

zh-CN/faq.md

@@ -141,9 +141,10 @@ Rust 维护三个“发行频道”：稳定版（stable）、测试版（beta
 我可以在 Beta 或稳定频道上使用不稳定的功能吗？
 </a></h3>
 
-并不能。Rust works hard to provide strong guarantees about the stability of the features provided on the beta and stable channels. When something is unstable, it means that we can't provide those guarantees for it yet, and don't want people relying on it staying the same. This gives us the opportunity to try changes in the wild on the nightly release channel, while still maintaining strong guarantees for people seeking stability.
+并不能。Rust努力保证测试版和每夜版的特性稳定性。当某些特性不稳定时，意味着我们还不能提供这种保证，不希望开发者依赖它。这给了我们在每夜版上适时尝试改变的机会，但是继续维护开发者寻求的稳定性。
+
+测试和稳定版每六周更新一次是固定的，偶然有测试版的修正被及时接受，你不想使用每夜版而等待希望的某个特性的话，你可以通过检查 [`B-unstable`](https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+tracking+label%3AB-unstable)标记跟踪尚存的问题。
 
-Things stabilize all the time, and the beta and stable channels update every six weeks, with occasional fixes accepted into beta at other times. If you're waiting for a feature to be available without using the nightly release channel, you can locate its tracking issue by checking the [`B-unstable`](https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+tracking+label%3AB-unstable) tag on the issue tracker.
 
 <h3><a href="#what-are-feature-gates" name="what-are-feature-gates">
 什么是“特性门控”（Feature Gates）？