Don’t try to cheat the taxman (税务人员); you’ll never ________it.

A．get out of

B．get into

C．get along

D．get away with

为明确某食物疗法对贫血的疗效，选用治疗前、后血红蛋白量作为疗效观察指标，这属于

A．实验对照
B．空白对照
C．安慰剂对照
D．标准对照
E．自身对照