第2题: [单项选择]He said the most unusual aspect of the Mexican trial was that the 12 teenagers were not given any drags to suppress their immune systems, ______ would normally destroy any cells from other animals. A. at which B. which C. to which D. as 参考答案:B
第23题: [单项选择]以下关于测量不确定度与测量误差的说法中，不正确的是（）。 A. 测量不确定度与测量误差都是描述测量结果的量 B. 测量不确定度与真值和测量结果无关 C. 测量不确定度与人们对被测量和影响量及测量过程的认识有关 D. 测量误差按性质可分为随机误差和系统误差两类，都是理想的概念 参考答案:B
