diff --git a/pptx/opc/pkgreader.py b/pptx/opc/pkgreader.py
index 59c74da53..2c03c2c2c 100644
--- a/pptx/opc/pkgreader.py
+++ b/pptx/opc/pkgreader.py
@@ -287,7 +287,11 @@ def load_from_xml(baseURI, rels_item_xml):
         """
         srels = _SerializedRelationshipCollection()
         if rels_item_xml is not None:
-            rels_elm = parse_xml(rels_item_xml)
-            for rel_elm in rels_elm.relationship_lst:
-                srels._srels.append(_SerializedRelationship(baseURI, rel_elm))
+            if 'NULL' in str(rels_item_xml):
+                print('NULL found and skiped')
+                pass
+            else:
+                rels_elm = parse_xml(rels_item_xml)
+                for rel_elm in rels_elm.relationship_lst:
+                  srels._srels.append(_SerializedRelationship(baseURI, rel_elm))
         return srels
diff --git a/tests/pptx_translate.py b/tests/pptx_translate.py
new file mode 100644
index 000000000..cba5d3af0
--- /dev/null
+++ b/tests/pptx_translate.py
@@ -0,0 +1,308 @@
+import json
+
+from pptx import Presentation
+from pptx.enum.shapes import MSO_SHAPE_TYPE
+
+import openpyxl
+from openpyxl import Workbook
+import datetime
+
+CN_PPTFILE='D:\\cn_v2.pptx'
+EN_PPTFILE='D:\\en_v2.pptx'
+EXCELFILE="translate_word.xlsx"
+TYPE_TEXT='text'
+TYPE_TABLE='tablet'
+SHEET_NAME_TEXT='text_cn_en'
+SHEET_NAME_TABLE='table_cn_en'
+
+def judge_pure_english(keyword):
+    return all(ord(c) < 128 for c in keyword)
+
+def appendToList(raw_text, textList):
+    print(raw_text)
+    if judge_pure_english(raw_text):
+        print('pure english,ignore,continue... ...')
+        return
+    textList.append(raw_text)
+
+def appendTableToList(raw_text, textList):
+    textList.append(raw_text)
+
+def deleteDupElemFromList(textList):
+    return list(set(textList))
+    #return sorted(set(textList), key = textList.index)
+
+#get all text from ppt file
+def ppt_catch_format_text(filename):
+    """
+    抓取PPT的内容，按段落返回
+    其中 filename 是PPT文件的路径
+    """
+    prs = Presentation(filename)
+    txtList = []
+    for x in range(len(prs.slides)):
+        # ---Only on text-boxes outside group elements---
+        for shape in prs.slides[x].shapes:
+            print(shape)
+            if hasattr(shape, "text"):
+                print('hasattr text in shape%s'%(shape))
+                raw_text = shape.text.encode('utf-8').strip().decode()
+                appendToList(raw_text,txtList)
+                #for paragraph in shape.text_frame.paragraphs:
+                #    print('----from paragraph-----')
+                #    appendToList(paragraph.text, txtList)
+        # ---Only operate on group shapes---
+        group_shapes = [shp for shp in prs.slides[x].shapes 
+                        if shp.shape_type ==MSO_SHAPE_TYPE.GROUP]
+        for group_shape in group_shapes:
+            print(group_shape)
+            for shape in group_shape.shapes:
+                print(shape)
+                if shape.has_text_frame:
+                    print('has_text_frame in shape%s'%(shape))
+                    #row_text=shape.text_framew.text
+                    raw_text = shape.text.encode('utf-8').strip().decode()
+                    appendToList(raw_text, txtList)
+                    
+                    #for paragraph in shape.text_frame.paragraphs:
+                    #    print('----from paragraph-----')
+                    #    appendToList(paragraph.text, txtList)
+    
+    prs.save(filename)
+    return txtList
+
+def tranvel_table(table, txtList):
+    rows=len(table.rows)
+    columns=len(table.columns)
+    for i in range(rows):
+        for j in range(columns):
+            raw_text=table.cell(i,j).text
+            print('tranvel_table text:%s'%(raw_text))
+            appendToList(raw_text,txtList)
+            #table.cell(i,j).text='A'+text
+
+def tranvel_table_replace(table, text_list_cn, text_list_en):
+    rows=len(table.rows)
+    columns=len(table.columns)
+    for i in range(rows):
+        for j in range(columns):
+            raw_text=table.cell(i,j).text
+            print('tranvel_table text:%s'%(raw_text))
+            raw_text = shape.text.encode('utf-8').strip().decode()
+            targetText=getTranslate(raw_text,text_list_cn,text_list_en)
+            print('targetText:%s'%targetText)
+            if targetText != None:
+                table.cell(i,j).text=targetText
+                print('replace ok')
+
+def ppt_catch_format_text_from_table(filename):
+    txtList = []
+    prs = Presentation(filename)
+
+    for x in range(len(prs.slides)):
+        # ---Only on table outside group elements---
+        for shape in prs.slides[x].shapes:
+            print(shape)
+            if shape.has_table:
+                print('1has_table in shape%s'%(shape))
+                table = shape.table
+                tranvel_table(table, txtList)
+                #appendTableToList(row_text,txtList)
+                #for paragraph in shape.text_frame.paragraphs:
+                #    print('----from paragraph-----')
+                #    appendToList(paragraph.text, txtList)
+        # ---Only operate on group shapes---
+        group_shapes = [shp for shp in prs.slides[x].shapes 
+                        if shp.shape_type ==MSO_SHAPE_TYPE.GROUP]
+        for group_shape in group_shapes:
+            print(group_shape)
+            for shape in group_shape.shapes:
+                print(shape)
+                if shape.has_table:
+                    print('g has_table in shape%s'%(shape))
+                    #row_text=shape.text_framew.text
+                    row_text = shape.table
+                    appendTableToList(row_text, txtList)
+                    
+                    #for paragraph in shape.text_frame.paragraphs:
+                    #    print('----from paragraph-----')
+                    #    appendToList(paragraph.text, txtList)
+
+    prs.save(filename)
+    return txtList
+
+
+def ppt_catch_format_text_from_datasource(filename):
+   txtList = []
+   return txtList
+
+#write word list to excel file
+def write_excel(filename, txt_list_cn, type):
+    text_list = deleteDupElemFromList(txt_list_cn)
+
+    if type==TYPE_TEXT:
+        sheetname=SHEET_NAME_TEXT
+    elif type==TYPE_TABLE:
+        sheetname=SHEET_NAME_TABLE
+    else:
+        return
+    #wb = Workbook()
+    wb = openpyxl.load_workbook(filename)
+    word_sheet = wb.create_sheet(sheetname)
+    #rowindex colindex startswith 1 in table
+    rowindex=1
+    for wordtxt in text_list:
+        print('s%se'%(wordtxt))
+        #wordtxt.replace('\\','\\\\')
+        if judge_pure_english(wordtxt):
+            print('pure english,ignore,continue... ...')
+            continue
+        word_sheet.cell(rowindex,1).value=wordtxt
+        rowindex=rowindex+1
+        #wordfile.write(wordtxt)
+        #wordfile.write(",")
+    wb.save(filename)
+
+def read_excel(filename, type):
+    text_list_cn = []
+    text_list_en = []
+    wb = openpyxl.load_workbook(filename)
+    #ws = wb.active
+    
+    if type==TYPE_TEXT:
+        sheetname=SHEET_NAME_TEXT
+    elif type==TYPE_TABLE:
+        sheetname=SHEET_NAME_TABLE
+    else:
+        return
+    word_sheet = wb[sheetname]
+    #print(list(word_sheet.columns)[0])
+    colA=word_sheet['A']
+
+    #print(colA)
+    #print(type(colA))
+    #print(colA.__class__)
+    #print(dir(colA))
+    colB=word_sheet['B']
+    for cell in colA:
+        text_list_cn.append(cell.value)
+    for cell in colB:
+        text_list_en.append(cell.value)
+    print(text_list_cn)
+    print(text_list_en)        
+
+    return text_list_cn,text_list_en
+
+
+#获得cn对应的翻译en
+def getTranslate(text,text_list_cn,text_list_en):
+    for index in range(len(text_list_cn)):
+        #print('search:%s index:%s value:%s'%(text,index,text_list_cn[index]))
+        if text_list_cn[index].strip() == text.strip():
+            return text_list_en[index]
+
+def replace_ppt_text(filename, text_list_cn, text_list_en, targetfilename):
+    prs = Presentation(filename)
+    for x in range(len(prs.slides)):
+        #txt_oa[x] = []
+        # ---Only on text-boxes outside group elements---
+        for shape in prs.slides[x].shapes:
+            print(shape)
+            if hasattr(shape, "text"):
+                print(shape.text)
+                raw_text = shape.text.encode('utf-8').strip().decode()
+                print('Sshape.textInPpt:%sE'%(shape.text))
+                print('Srow_textInPpt:%sE'%(raw_text))
+                targetText=getTranslate(raw_text,text_list_cn,text_list_en)
+                print('targetText:%s'%targetText)
+                if targetText != None:
+                    shape.text=targetText
+                    print('replace ok')
+
+        # ---Only operate on group shapes---
+        group_shapes = [shp for shp in prs.slides[x].shapes 
+                        if shp.shape_type ==MSO_SHAPE_TYPE.GROUP]
+        for group_shape in group_shapes:
+            for shape in group_shape.shapes:
+                if shape.has_text_frame:
+                    raw_text = shape.text.encode('utf-8').strip().decode()
+                    print('Sshape.textInPpt:%sE'%(shape.text))
+                    print('Srow_textInPpt:%sE'%(raw_text))
+                    targetText=getTranslate(raw_text,text_list_cn,text_list_en)
+                    print('targetText:%s'%targetText)
+                    if targetText != None:
+                        shape.text=targetText
+                        print('replace ok')
+    
+    prs.save(targetfilename)
+
+def replace_ppt_table(filename, text_list_cn, text_list_en, targetfilename):
+    prs = Presentation(filename)
+    for x in range(len(prs.slides)):
+        #txt_oa[x] = []
+        # ---Only on text-boxes outside group elements---
+        for shape in prs.slides[x].shapes:
+            if shape.has_table:
+                print('1has_table in shape%s'%(shape))
+                table = shape.table
+                tranvel_table_replace(table, text_list_cn, text_list_en)
+
+    prs.save(targetfilename)
+
+
+    
+def python_help():
+    print('---------------get cn word from pptx-----------------------')
+    text_list = ppt_catch_format_text('E:\D\sec.pptx')
+    print('---------------write word to xlsx-----------------------')
+    write_excel("word.xlsx",text_list)
+    #text_list = json.dumps(text_list, ensure_ascii=False, indent=4).replace("\\n","")
+    print('--------------------------------------')
+    print(text_list)
+    print(text_list.__class__)
+    #print(text_list.__base__)
+    print(dir(text_list))
+
+    print(type(text_list))
+    print(type(type(text_list)))
+
+    print('--------------------------------------')
+    #print(text_list.object)
+    #print(text_list.__str__)
+    #wordfile.write("\n")
+
+CMD1='READ text'
+CMD2='READ table'
+CMD3='WRITE text'
+CMD4='WRITE table'
+def main():
+    print('---------------enter main()-----------------------')
+    cmd=1
+    print('---------------enter CMD:%d-----------------------'%cmd)
+    if cmd==1:
+        text_list=ppt_catch_format_text(CN_PPTFILE)
+        print(text_list)
+        write_excel(EXCELFILE,text_list,TYPE_TEXT)
+    elif cmd==2:
+        text_list=ppt_catch_format_text_from_table(CN_PPTFILE)
+        print(text_list)
+        write_excel(EXCELFILE,text_list,TYPE_TABLE)
+    elif cmd==3:
+        #maybe excel format changed, cannot compare
+        text_list_cn,text_list_en=read_excel(EXCELFILE,TYPE_TEXT)
+        print('---------------after read_excel-----------------------')
+        print(text_list_cn)
+        print(text_list_en)
+        print('---------------enter replace_ppt-----------------------')
+        replace_ppt_text(CN_PPTFILE,text_list_cn, text_list_en, EN_PPTFILE)
+    elif cmd==4:
+        text_list_cn,text_list_en=read_excel(EXCELFILE,TYPE_TABLE)
+        print('---------------after read_excel-----------------------')
+        print(text_list_cn)
+        print(text_list_en)
+        print('---------------enter replace_ppt-----------------------')
+        replace_ppt_table(CN_PPTFILE,text_list_cn, text_list_en, EN_PPTFILE)
+
+    
+main()
+#AF_INET域 AF_UNIX
\ No newline at end of file