Very minor language improvements

ca.tex

@@ -7857,7 +7857,7 @@ \section{Homology versions of Cauchy}
 usually written $H_1(U)$.
 \item
 Compute $H_1(\C \setminus \{ 0 \})$ (that is,
-find what group is it isomorphic to).
+find what group it is isomorphic to).
 \end{exparts}
 \end{exercise}
 
@@ -7905,7 +7905,7 @@ \section{Simply connected domains}
 perhaps not the standard definition, but for domains in $\C$
 (connected open sets)
 it is equivalent to the correct one.
-We will define the term \myquote{properly} once we get 
+We will define the term properly once we get 
 to homotopy.\footnote{Homotopy is in an optional section, which is the
 reason why we make this \myquote{wrong} definition.}
 We may sometimes say
@@ -8990,7 +8990,8 @@ \subsection{Homotopy}
 \end{exercise}
 
 \begin{exercise}
-We could take a different approach to solving our issues with homotopy.  Let
+We could take a different approach to solving our issues with the regularity
+of the homotopy.  Let
 $U \subset \C$ be open and let $\gamma_0$ and $\gamma_1$ be closed
 piecewise-$C^1$ paths in $U$ that are homotopic in $U$.
 Show that there exists a homotopy (possibly different one) such that