发病率可用来（）。
A.描述疾病的分布
B.探讨发病的因素
C.评价预防措施的效果
D.提出病因假设
E.研究死亡的严重程度
参考答案：A, B, C, D
小明付a元买单件是0.5元的白纸x张，应找回______元．
The nurse is speaking to grieving parents after a sudden infant death syndrome (SIDS) death. What should the nurse emphasize to the parents（）
A. The death couldn’t have been prevented and isn’t the parents’ fault.
B. The parents must allow an autopsy to confirm the diagnosis.
C. The parents are still young and can have more children.
D. The parents should place other infants on their backs to sleep.
