"Doctor, are you sure I''m suffering from pneumonia? I''ve heard once about a doctor treating someone with pneumonia and finally he died of typhus."
"Don''t worry, it won''t happen to you. If I treat someone with pneumonia he will die of pneumonia only." . . . ;->
Teacher : Correct the sentence, "A bull and a cow is grazing in the Field"
Student : A cow and a bull is grazing in the field
Teacher : How?
Student : Ladies First