\only<${1:NUM:}>{
${2:TARGET}
}
+
+snippet exercise
+abbr exercise (exsheet)
+alias \begin{exercise} \exercise
+ \begin{exercise}
+ ${1:TARGET}
+ \end{exercise}
+
+snippet choices
+abbr choices (exsheet)
+alias \begin{choices} \choices
+ \begin{choices}
+ ${1:TARGET}
+ \end{choices}