资料收集的质量控制不包括()
A.划分接触和健康效应指标明确
B.选择代表性的调查对象
C.消除各组实验外其他因素
D.尽量取得定量资料
E.重视资料复核
参考答案:B
Concerning the payment for the machines to be imported by us, we suggest that we make payment ______ three annual installments without interest.
A.byB.withC.for D.on
应该如何治疗山羊传染性脓疱?