Two stylistic suggestions

_episodes/05-history.md

@@ -351,6 +351,12 @@ moving backward and forward in time becomes much easier.
 > 4. `$ git checkout <unique ID of last commit> data_cruncher.py`
 >
 > 5. Both 2 and 4
+> > ## Solution
+> > `git checkout HEAD` does not check out that specific file
+> > `$ git checkout HEAD data_cruncher.py` works to recover her previously committed version
+> > `$ git checkout HEAD~1 data_cruncher.py` checks out the version from 2 commits ago (one before the most recent one called HEAD)
+> > `$ git checkout <unique ID of last commit> data_cruncher.py` also recovers her previously committed version
+> {: .solution}
 {: .challenge}
 
 > ## Reverting a Commit

_episodes/09-conflict.md

@@ -308,9 +308,9 @@ consider these technical approaches to reducing them:
 Conflicts can also be minimized with project management strategies:
 
 - Clarify who is responsible for what areas with your collaborators
-- Discuss what order tasks should be carried out in with your collaborators so
+- Discuss what order tasks should be carried out with your collaborators so
   that tasks expected to change the same lines won't be worked on simultaneously
-- If the conflicts are stylistic churn (e.g. tabs vs. spaces), establish a
+- If the conflicts are due to differences in style (e.g. tabs vs. spaces), establish
   project convention that is governing and use code style tools (e.g.
   `htmltidy`, `perltidy`, `rubocop`, etc.) to enforce, if necessary
 
@@ -332,7 +332,7 @@ Conflicts can also be minimized with project management strategies:
 >
 > > ## Solution
 > >
-> > Let's try it. Suppose Dracula takes a picture of Martian surface and
+> > Let's try it. Suppose Dracula takes a picture of the Martian surface and
 > > calls it `mars.jpg`.
 > >
 > > If you do not have an image file of Mars available, you can create
@@ -501,7 +501,7 @@ Conflicts can also be minimized with project management strategies:
 >
 > - *Make changes* by appending the number `100` to a text file `numbers.txt`
 > - *Update remote* repository to match the local repository
-> - *Celebrate* your success with beer(s)
+> - *Celebrate* your success with your choice of delicious beverage!
 > - *Update local* repository to match the remote repository
 > - *Stage changes* to be committed
 > - *Commit changes* to the local repository
@@ -519,7 +519,7 @@ Conflicts can also be minimized with project management strategies:
 > |3    |                           |                            |
 > |4    |                           |                            |
 > |5    |                           |                            |
-> |6    | Celebrate!                | `AFK`                      |
+> |6    | Celebrate!                |                            |
 >
 > > ## Solution
 > >
@@ -530,7 +530,7 @@ Conflicts can also be minimized with project management strategies:
 > > |3    | Stage changes     | `git add numbers.txt`                        |
 > > |4    | Commit changes    | `git commit -m "Add 100 to numbers.txt"`     |
 > > |5    | Update remote     | `git push origin master`                     |
-> > |6    | Celebrate!        | `AFK`                                        |
+> > |6    | Celebrate!        |                                              |
 > >
 > {: .solution}
 {: .challenge}