
某年8月,某村在一周的时间内突然发生多例畏寒、发热、腹痛、腹泻病例,区疾病控制中心接到报告,立即组织调查处理。在流行病学的调查或研究中,通常采取以下哪些方法尽量控制流行病学中的可能偏倚()。
A . A.对病例和对照设定详尽的排除和纳入标准
B . 匹配
C . 随机化分组
D . 重复试验或调查
E . 按不同因素进行分层分析
F . 多因素分析


A . A.对病例和对照设定详尽的排除和纳入标准
B . 匹配
C . 随机化分组
D . 重复试验或调查
E . 按不同因素进行分层分析
F . 多因素分析
Listening and speaking: Passage
Task 2 Now listen to the passage again. Complete the following outline about the conditions of experiencing “love at first sight” and the possible results.
A. Conditions of experiencing “love at first sight”:
1 There must be some type of 1)_________ attraction.
2 Both people have personalities that are 2)___________ and 3)__________ to each other.
3 Both people must feel 4)__________ that the other person 5)__________ them.
4 Both must be at a place in their life to be 6)_______ to be 7)________.
B. Possible results of “love at first sight”:
1 A happy ending: Some eventually marry, 8)______a family and 9)_____________for the rest of their lives.
2 An unhappy ending: Experiencing “love at first sight” doesn't 10)__________that the connection will remain 11)________. Many find themselves 12)________ out of love and 13)__________.