Which of the following are the discharge criteria for COVID-19 patients? A: Body temperature returns to normal for more than 3 days. B: Respiratory symptoms improve significantly. C: Pulmonary imaging shows significant improvement in acute exudative lesions. D: Respiratory specimens are tested negative in nucleic acid tests, such as sputum and nasopharyngeal swabs, for two consecutive times (sampling interval shall be at least 24 hours). E: Patients have no obvious cough and expectoration.