Mr White ____ the newspaper while his daughter ____TV. [ ]

A. has read; was watching

B. was reading; watched

C. was reading; was watching

D. reading; watched

现况调查中偏倚的防止方法主要是（）。

A.坚持随机化抽样，减少漏查，统一检测标准，加强调查的监督和质控

B.坚持多个医院选择病例，减少漏查，统一检测标准，加强调查的监督和质控

C.坚持随机化分组，减少不依从，统一检测标准，加强调查的监督和质控

D.坚持随机化选择研究对象，尽量用新发病例，暴露测量标准应统一，加强调查的监督和质控

E.以上方法都不对