流行病学实验具有以下特点() A.病例组、对照组均有干预措施 B.暴露组、非暴露组均 发布时间:2017-05-06 13:44 │ 来源:www.tikuol.com 题型:单项选择题 A1/A2型题 问题: 流行病学实验具有以下特点()A.病例组、对照组均有干预措施B.暴露组、非暴露组均有干预措施C.在实验室中进行D.随机原则、设立对照组、有干预措施E.属于观察性研究
题型:单项选择题 A1/A2型题 More has been learned about the Moon than any other of the Earth's neighbors in space because of the Apollo program, which enabled men to walk on the Moon and bring back hundreds of pounds of ______.A.rocksB.rockC.stoneD.stones 查看答案