 Patients in biomarker treatment arm and FENO25ppb were given Montelukast Sodium Tablets p.o., 10mg, q.d. . Patients in biomarker reatment arm and FENO25ppb were given placebo p.o., 10mg, qd. Patients in standard treatment arm and FENO25ppb were given placebo p.o., 10mg, qd. Patients in standard treatment arm and FENO25ppb were given Montelukast Sodium Tablets p.o., 10mg, q.d. .All treatment regimens lasted for 10 days and no other antitussivedecongestant or bronchodilators are given to any patients. 