题目: 病因网(络)模型的主要优点是()A.涉及因素具体且可操作性强B.涉及的因素清晰具体且系统性强C.没有确定必要病因的困难D.没有确定充分病因的困难E.涉及的病因链较多且相互交错 答案: 参考答案:B
题型:选择题 —Where is Jack, please? —He _____ be in the reading room. [ ]A. need B. shall C. must D. would 查看答案