正常成人从上切牙到气管隆嵴的距离为()
A.17~19cm
B.20~22cm
C.23~25cm
D.26~28cm
E.29~31cm
参考答案:C
Mrs Black doesn’t believe her son is able to design a digital camera,________?[ ]
A.is he
B.isn’t he
C.doesn’t she
D.does she
简述建立学习档案袋的步骤。