[填空题]Theories have features that are (indicative of) their truth, and the task of justification to identify these features and (using them) to guide choices (as to) (which theories) believe.
A. indicative of B. using them C. as to D. which theories
第14题: [单项选择]造成脑电图缺血改变的脑血流阈值是 A. 6ml/100g/min B. 15ml/100g/min C. 22ml/100g/min D. 31ml/100g/min E. 40ml/100g/min 参考答案:C 答案解析:脑血流低于50ml/(100g·min)的正常水平时仍能维持正常的神经功能。在脑血流低于22ml/(100g·min)前,脑血流提供的氧不会引起脑电图缺血改变。脑血流达到15ml/100g/min时脑