《学记》要求“学不躐等”、“不陵节而施”。这个要求反映的教学原则是（）
A.巩固性原则
B.循序渐进原则
C.因材施教原则
D.直观性原则
参考答案：B
He _____ without saying good-bye to them, for he always has good manners.
A．mustn’t have left
B．may not leave
C．shouldn’t have left
D．can’t have left
换气功能监测的内容不包括（）
A.二氧化碳弥散量DLCO2
B.肺泡动脉氧分压差A-aDO2
C.肺内分流量QS和分流率QS/QT
D.动脉氧分压PaO2与氧合指数PaO2/FiO2
E.脉搏血氧饱和度SPO2
He _____ without saying good-bye to them, for he always has good manners.