病例对照研究中哪一项是错误的()。
A.着重在因果关系分析
B.可计算发病率
C.可计算比值
D.可能产生偏差
E.对照组要求不患所研究疾病或病因相似疾病
参考答案:B
Jenny doesn’t want to go swimming because she’s _____ getting into water. [ ]
A. good at
B. angry with
C. terrified of
D. interested in
氮气中串进氨气后,其水溶液呈碱性。