GRE Text Completion: JiJing 1373-GRE填空机经1373题 - TM5N40O87DQC6BINA

The professor's habitual air of ____________ was a misleading front, concealing amazing reserves of patience and a deep commitment to his students' learning. A. cordiality B. irascibility C. disorganization D. conviviality E. diffidence F. exasperation