README.md in zip_code-0.1.3 vs README.md in zip_code-0.1.4

@@ -20,13 +20,17 @@
 
     $ gem install zip_code
 
 ## Usage
 
-TODO: Write usage instructions here
+```ruby
+zip_code = ZipCode.find('河北省', '邢台市')
+puts zip_code # => "054000"
 
+zip_code = ZipCode.find('河北省', '邢台市', '柏乡县')
+puts zip_code # => "055450"
+```
 ## Development
-
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
 ## Contributing