除发现下列哪种情况时，说明绷带缚得太紧应该解开重新固定（）
A.苍白
B.青紫
C.红润
D.冰冷
E.麻木
参考答案：C
It was not until she arrived at the classroom she realized she had forgotten her coursebook.
A．and she realized
B．which she realized
C．then she realized
D．that she realized
流行病学研究对象的三个层次是指
A．疾病、伤害、健康B．病人、非病人、一般人群C．传染病、慢性病、慢性非传染性疾病D．死亡、患病、健康E．疾病、健康、突发事件
