在锅炉运行中，送、引风量是否相适应是以（）的负压作为被调量来表征的。
A、炉膛上部
B、炉膛下部
C、炉膛中部
D、烟道内
参考答案：A
As technological advances put more and more time between early school life and the young person''s final access to specialized work, the stage of ________becomes an even more marked and conscious period.
A．adolescence
B．adjacency
C．advantage
D．adventure
效用(Utility）
