Update CMB.py

CMB.py

@@ -107,7 +107,6 @@ class CMB(datasets.GeneratorBasedBuilder):
             features=datasets.Features(
                 {
                     "id": datasets.Value("string"),
-                    "source": datasets.Value("string"),
                     "exam_type": datasets.Value("string"),
                     "exam_class": datasets.Value("string"),
                     "exam_subject": datasets.Value("string"),
@@ -247,7 +246,7 @@ class CMB(datasets.GeneratorBasedBuilder):
             for idx in range(len(examples)):
                 vals = examples[idx]
                 vals['answer'] = vals.get('answer','')
-                vals['source'] = vals.get('source','')
+                
                 vals['id'] = vals.get('id',idx)
                 yield idx, vals