燃气锅炉自动调节系统是根据锅炉出口蒸汽压力的变化来改变天然气流量（）阀开度的。
A.调节
B.减压
C.安全
D.空气
参考答案：A
1. Would you please __the paper for me and see if there are any obvious mistakes?
A．look around
B．look into
C．look up
D．look through
视觉在鱼类集群行为中的作用
