债券的特征之一是参与性。
参考答案:错
She was afraid of _______ SARS because it was dangerous.[ ]
A. catch
B. catches
C. caught
D. catching
发作性吸气性呼吸困难,临床最常见于()
A.气胸
B.气管内异物
C.急性支气管炎
D.急性心肌梗死
E.哮喘