来自同一总体的两样本，下列哪个指标小的样本均数估计总体均数时更可靠（）
A．S
B．CV
C．S
D．t0.05,v·S
E．
参考答案：A
26. The little girl showed no anxiety before the competition. She seemed _____ for it pretty well.
A．to prepare
B．to have prepared
C．having prepared
D．to be preparing
下列有关大肠功能的叙述，不正确的是[ ]
A．吸收氨基酸
B．将食物残渣形成粪便
C．吸收水和无机盐
D．吸收某些维生素
