clarify sentence on arduino holes

diff --git a/guide/challenge-bot-questions.org b/guide/challenge-bot-questions.org
index d3849a51c771b8a652e69e1085245deeafd8d1d7..4246fe3acc435449a6ba615c202a891cbe17be13 100644 (file)
--- a/guide/challenge-bot-questions.org
+++ b/guide/challenge-bot-questions.org
@@ -10,7 +10,8 @@
     2. why did we use a drill bit that was wider than the body of the
        bolt used to hold the arduino?
     3. why do people use drill bits that are smaller or the same size as
-       existing holes in circuit boards, like the blue arduino?
+       existing holes in circuit boards, like the holes in the blue
+       arduino?
     4. why did we drill through the arduino, rather than marking holes
        and using the drill to make holes where the marks were?
     5. how does the drill hold onto the drill bit?