fix bug

app/views/homework_commons/works_list.xlsx.axlsx

@@ -2,8 +2,8 @@
 wb = xlsx_package.workbook
 wb.use_autowidth = false
 wb.styles do |s|
-  sz_all = s.add_style :border => { :style => :thin, :color =>"000000" },:alignment => {:horizontal => :center}
+  sz_all = s.add_style :border => { :style => :thin, :color =>"000000" },:alignment => {wrap_text: true,:horizontal => :center}
-  blue_cell = s.add_style :bg_color => "FAEBDC", :sz => 10,:height => 20,:b => true, :border => { :style => :thin, :color =>"000000" },:alignment => {:horizontal => :center}
+  blue_cell = s.add_style :bg_color => "FAEBDC", :sz => 10,:height => 20,:b => true, :border => { :style => :thin, :color =>"000000" },:alignment => {wrap_text: true,:horizontal => :center}
   wb.add_worksheet(:name => "学生成绩") do |sheet|
     sheet.sheet_view.show_grid_lines = false
     sheet.add_row table_columns, :style => blue_cell