调查者事先知道谁是病例谁是对照易发生（）

A.选择偏倚

B.信息偏倚

C.混杂偏倚

D.选择偏倚和混杂偏倚

E.信息偏倚和混杂偏倚

His jewelry shop is said ____ and he can’t help but____ the fact.

A．robbing; to accept

B．to rob; accepts

C．to have robbed; accept

D．to have been robbed; accept