fix bug

app/templates/exercise_export/blank_exercise.html.erb

@@ -79,14 +79,14 @@
             <div class="pbt5">
               <% if q.question_type ==  0 %>
                 <% q.exercise_choices.each do |s| %>
-                  <div class="pbt5 clearfix v-middle">
+                  <div class="pbt5 clearfix">
                     <span class="choose-radio pull-left line-24"></span>
                     <span class="inline-block pull-left line-24"><%= to_markdown(s.choice_text) %></span>
                   </div>
                 <% end %>
               <% elsif q.question_type == 1 %>
                 <% q.exercise_choices.each do |s| %>
-                  <div class="pbt5 clearfix v-middle">
+                  <div class="pbt5 clearfix">
                     <span class="choose-checkbox pull-left line-24"></span>
                     <span class="inline-block pull-left line-24"><%= to_markdown(s.choice_text) %></span>
                   </div>

app/templates/exercise_export/exercise_export.css

@@ -312,11 +312,9 @@ textarea{
 .line-24{
     line-height: 24px;
 }
-.line-20 P{
+.line-24 p{
     margin-bottom:0;
 }
-.v-middle{
-    vertical-align: middle;
-}
+