Fix grammar

Closes modelica#3445

chapters/annotations.tex

@@ -622,7 +622,7 @@ \section{Graphical Objects}\label{annotations-for-graphical-objects}\label{graph
 \end{example}
 
 The graphics is specified as an ordered sequence of graphical primitives, which are described below.
-First base class contents is drawn according to the order of the \lstinline!extends!-clauses, and then graphical primitives are drawn according to the order such that later objects can cover earlier ones.
+First, base class contents are drawn according to the order of the \lstinline!extends!-clauses, and then graphical primitives are drawn according to the order such that later objects can cover earlier ones.
 
 \begin{nonnormative}
 Note that the ordered sequence is syntactically a valid Modelica annotation, although there