流行病学实验中可比性较好的对照不包括
A．安慰剂对照
B．标准疗法对照
C．历史对照
D．自身对照
E．交叉对照
参考答案：C
— I have some exciting news to tell you. Our school has been named a model high school.
— _____. That's really great![ ]
A. Pardon?
B. Has it?
C. Good idea
D. Congratulations!
下列不属于施工合同竣工验收纠纷成因的是()。
A．隐蔽工程验收产生的纠纷
B．因验收标准、范围和程序等问题导致的纠纷
C．合同工期约定不合理
D．未经竣工验收而提前使用导致的纠纷
