app/views/search_results/sections/_mode.html.erb
<div class="form-group">
<%= label_tag :qt, t('txt.views.search_results.mode') %>
<%= select_tag :qt, options_for_select([
[t('txt.views.search_results.contains'), 'contains'],
[t('txt.views.search_results.exact'), 'exact'],
[t('txt.views.search_results.ends_with'), 'ends_with'],
[t('txt.views.search_results.begins_with'), 'begins_with']
], params[:qt]), :class => 'form-control' %>
</div>