updates from comments in PR

docs/Basic-Guide.md

    **Note**: The Unity prefab system will modify all instances of the agent properties in your scene.  If the agent does not synchronize automatically with the prefab, you can hit the Revert button in the top of the **Inspector** window.
 
 2. In the **Hierarchy** window, select `Ball3DAcademy`.
-3. In the **Project** window, go to `Assets/ML-Agents/Examples/3DBall/Brains` folder and drag the **3DBallLearning** Brain to the `Brains` property under `Braodcast Hub` in the `Ball3DAcademy` object in the **Inspector** window.  In order to train, make the `Control` checkbox is selected.
+3. In the **Project** window, go to `Assets/ML-Agents/Examples/3DBall/Brains` folder and drag the **3DBallLearning** Brain to the `Brains` property under `Braodcast Hub` in the `Ball3DAcademy` object in the **Inspector** window.  In order to train, make sure the `Control` checkbox is selected.
-The `Control` checkbox means that in addition to being exposed to Python, the agent Brain will
+The `Control` checkbox means that in addition to being exposed to Python, the Brain will
 be controlled by the Python process (required for training).
 
    ![Set Brain to External](images/mlagents-SetBrainToTrain.png)