The width of airway is _______ km, and due to some constraints, should not be less than _______km.
A.10, 5
B.20, 8
C.15, 7.5
D.30, 15
正确答案是B
The width of airway is _______ km, and due to some constraints, should not be less than _______km.
A.10, 5
B.20, 8
C.15, 7.5
D.30, 15
正确答案是B