fixed exercises, add speaker notes to parts 1 and 4

exercises/Exercise 1a Local imports.md

@@ -2,7 +2,7 @@
 
 #### Goal
 
-Retrival practice in "basic" importing.
+Retrieval practice in "basic" importing.
 
 #### Preparation
 
@@ -28,7 +28,7 @@ pizza, drink = todays_special()
 ```
 
 1. Figure out what import statements are missing, either by visual inspection or
-   by running the code and seeing what does. Add the missing import statements at
+   by running the code and seeing what it does. Add the missing import statements at
    the top of the file. You may need to inspect the files in `src/italianfood/`.
 
 2. Run `daily_menu.py`. Did it work?

exercises/Exercise 1b Unprotected code.md

@@ -10,13 +10,13 @@ Investigate what happens when importing from modules with "unprotected" code.
 
 #### Tasks
 
-0. Create a file in the `src/` folder called `unprotectd_code.py`.
+0. Create a file in the `src/` folder called `unprotected_code.py`.
 
-1. Add a line in `unprotectd_code.py` that imports the `todays_special` function from `daily_menu.py`.
+1. Add a line in `unprotected_code.py` that imports the `todays_special` function from `daily_menu.py`.
 
-2. **BEFORE YOU EXECUTE THE FILE**. Discuss with your partner what you think will happen when you run `unprotectd_code.py`.
+2. **BEFORE YOU EXECUTE THE FILE**. Discuss with your partner what you think will happen when you run `unprotected_code.py`.
 
-3. Run `unprotectd_code.py`. Does your prediction match reality?
+3. Run `unprotected_code.py`. Does your prediction match reality?
 
 4. (optional, for those who know) Discuss with your partner:
     * Why did this behaviour occur?