非接触式密封,常用的有()和()。
参考答案:油沟式密封槽;迷宫式密封槽
保留灌肠时,肛管插入肛门长度约()
A.4~6cm
B.7~10cm
C.10~15cm
D.15~18cm
E.15~20cm
Stimulus-response theory of learning belongs to American behaviourist psychology, of which______ is one of the representatives.
A.Bloomfield
B.B.F. Skinner
C.Charles Fries
D.Noam Chomsky